Straits Times Index
The Straits Times Index (STI) is a market capitalization-weighted stock market index that tracks the performance of the top 30 largest and most liquid companies listed on the main board of the Singapore Exchange (SGX).[1] It serves as the primary benchmark for the Singapore equity market, providing a key indicator of the overall health and direction of the nation's economy.[2] With a history dating back to 1966, the STI was originally developed by the Straits Times newspaper and has since evolved to reflect Singapore's growing and diversifying economy, incorporating companies across sectors such as finance, real estate, and technology.[3] Today, it is jointly maintained and calculated by FTSE Russell in collaboration with SPH Media Ltd. and SGX, using a free-float-adjusted market capitalization methodology that ensures representation of investable market opportunities.[4] The index undergoes semi-annual reviews to adjust for changes in company rankings based on full market capitalization and liquidity criteria, with constituents selected from the broader FTSE ST All-Share Index universe.[4] As Singapore's most globally recognized market barometer, the STI underpins a wide range of financial products, including exchange-traded funds (ETFs), derivatives, and structured investments, facilitating benchmarking for institutional and retail investors worldwide.[2] Its performance is disseminated in real-time during SGX trading hours, offering intra-second updates to capture market dynamics effectively.[4]Overview
Definition and Purpose
The Straits Times Index (STI) is a capitalization-weighted index that comprises the 30 largest and most liquid companies listed on the Singapore Exchange (SGX).[1] It tracks the overall performance of these blue-chip stocks, representing approximately 85% of the total market capitalization of the SGX main board.[5] The primary purpose of the STI is to serve as a key benchmark for the Singapore equity market, offering investors a reliable indicator of the health and direction of the nation's leading corporations.[6] By focusing on highly traded and established firms, it reflects the broader economic vitality of Singapore, particularly through exposure to dominant sectors such as finance, real estate, and industrials.[3] This makes the index a vital tool for portfolio management, performance evaluation, and gauging investor sentiment in Southeast Asia's financial hub. The index's history dates back to 1966 with its predecessor, the Straits Times Industrials Index (STII). The STI was launched on 31 August 1998 as a capitalization-weighted index, replacing the STII to provide a more representative measure of Singapore's stock market following developments in the financial sector.[7] Its base value was established at 885.26 points on 31 August 1998 during the transition to its modern capitalization-weighted form, ensuring continuity with historical data while adapting to contemporary market dynamics.[8]Key Characteristics
The Straits Times Index (STI) is constructed using a capitalization-weighted methodology that relies on free-float adjusted market capitalization, where the weight of each constituent is determined by the portion of its shares available for public trading.[1] This approach ensures that the index reflects the investable opportunity set in the Singapore market, prioritizing liquidity and accessibility.[5] Comprising 30 large-cap constituents, the STI captures approximately 85% of the total market capitalization on the Singapore Exchange (SGX), providing broad representation of the local equity market.[5] As of October 2025, the index's total free-float adjusted market capitalization was approximately S$408 billion, underscoring its scale within the SGX ecosystem.[9] The index demonstrates sector diversification, with financial services holding the heaviest weighting at around 54%, exemplified by major banks like DBS Group Holdings.[3] This is followed by real estate (approximately 16%) and industrials (about 10%), contributing to a balanced exposure across key economic sectors such as telecommunications, utilities, and consumer goods.[9] Free-float adjustment excludes shares held by governments or closely held entities, focusing solely on publicly tradable portions to enhance accuracy and relevance for investors.[5]History
Establishment and Early Development
The Straits Times Index (STI) originated in 1966 as the Straits Times Industrial Index (STII), launched by The Straits Times newspaper in partnership with the Stock Exchange of Singapore to benchmark the performance of the nation's burgeoning industrial sector following independence in 1965. Designed to capture the vitality of Singapore's post-colonial economy, the index began as a price-weighted measure with a base value of 100, effective from December 30, 1966. It focused primarily on industrial and trading companies, providing investors and policymakers with a vital gauge of market health amid rapid industrialization efforts.[10][5] In its early years, the STII comprised approximately 25 to 30 leading stocks, emphasizing sectors like manufacturing and commerce that drove Singapore's economic expansion. The index mirrored the country's resilience during the 1970s oil crises, which disrupted global trade but spurred local diversification into petrochemicals and shipping, and tracked the robust recovery of the 1980s, fueled by export-oriented growth and foreign investment. By the mid-1980s, the first significant adjustments were made to broaden sector inclusion beyond pure industrials, incorporating emerging areas like property and services to better align with Singapore's evolving economic structure. These changes helped the index rise steadily, reflecting average annual GDP growth exceeding 8% through the decade.[11][12] A pivotal transition occurred on August 31, 1998, when the STII was supplanted by the modern STI, shifting to a market capitalization-weighted methodology with an initial base value of 885.26 points and 55 constituents drawn from a wider array of sectors, including banking and telecommunications. This revamp addressed the limitations of the price-weighted STII and accommodated Singapore's transformation into a global financial center. The new STI endured the 1997 Asian financial crisis, plummeting about 60% from its 1997 peak to a low in 1998, yet demonstrated underlying strength with post-crisis rebounds that underscored the economy's adaptability before major 21st-century overhauls.[13][5][14]Major Revamps and Changes
The Straits Times Index (STI) underwent a major revamp and relaunch on 10 January 2008, established through a partnership between Singapore Press Holdings (SPH), the Singapore Exchange (SGX), and FTSE (now part of FTSE Russell), which assumed responsibility for its calculation and management.[15] This overhaul shifted the index from its prior full market capitalization weighting to a free-float adjusted market capitalization methodology, while standardizing the number of constituents at exactly 30 to emphasize liquidity and investability among the largest SGX Mainboard-listed companies.[5][16] The primary rationale for these 2008 changes was to mitigate criticisms of the index's earlier structure, which suffered from over-reliance on a handful of dominant stocks, and to better align it with global standards exemplified by indices like the FTSE 100.[15] By adopting FTSE's rigorous eligibility criteria—including a minimum free-float of 15% and liquidity thresholds such as median daily turnover of at least 0.05% of free-float adjusted shares—the revamp aimed to enhance transparency, diversification, and the development of index-linked financial products.[15] Post-2008, the STI implemented quarterly reviews alongside semi-annual full assessments to incorporate eligible initial public offerings (IPOs) more swiftly and reflect ongoing market dynamics.[5] In 2015, liquidity screening rules were strengthened to further ensure the index's investability. In the 2010s, the index expanded its scope by admitting Real Estate Investment Trusts (REITs) and business trusts, starting with the inclusion of Ascendas REIT in June 2014, to capture a wider range of Singapore's asset classes amid the growth of its REIT market, the second-largest in Asia. In 2023, Venture Corporation became the first locally listed technology company added to the STI.[5][17] In the 2020s, the STI saw minor adjustments integrating environmental, social, and governance (ESG) factors into its framework to align with global sustainability trends, while navigating post-COVID economic recovery efforts; the index endured notable temporary volatility during the 2020 market crash, with a sharp decline of about 25% from its early 2020 peak to a low in late March before rebounding.[5] Overall, these transformations have bolstered the STI's international comparability—evidenced by its low correlation (around 0.6) with major indices like the Russell 1000—and heightened its appeal to global investors, supporting growth in the total market capitalization of constituents from under S$300 billion in 2008 to approximately S$408 billion as of October 2025.[5][16]Methodology
Calculation Method
The Straits Times Index (STI) is calculated using a free-float adjusted market capitalization-weighted methodology. The index value is determined by the formula: \text{STI} = \left( \frac{\text{Current Total Free-Float Adjusted Market Capitalization}}{\text{Base Market Capitalization}} \right) \times \text{Base Index Value} where the current total free-float adjusted market capitalization is the sum across all constituents of (price per share × number of free-float adjusted shares outstanding), the base market capitalization is derived from the initial constituents on the base date, and the base index value is set at launch.[18] This approach ensures the index reflects the aggregate investable market value of its components, with larger companies exerting greater influence proportional to their free-float adjusted size.[18] Free-float adjustment accounts for the portion of shares available for public trading, excluding those held by strategic investors, governments, or insiders above specified thresholds (typically promoter holdings exceeding 15-50% depending on the category). The investability weighting factor (ranging from 0 to 1) is applied to each constituent's shares outstanding to derive the free-float shares, ensuring only liquid, publicly accessible equity is included in the market cap calculation; companies with free float of 15% or less are ineligible for inclusion.[18] The STI is computed daily in real-time during Singapore Exchange (SGX) trading hours, from 9:00 AM to 12:00 PM and 1:00 PM to 5:00 PM Singapore Time (SGT), using the most recent trade prices for each constituent. The official end-of-day value is based on closing prices at 5:00 PM SGT, sourced from SGX data.[18][19] The base period for the STI is 31 August 1998, when it was revamped to a broader, value-weighted structure with an initial base market capitalization calculated from the then-constituent stocks.[5] Corporate actions are handled through a divisor adjustment methodology to preserve index continuity without distorting the value on the ex-date. For stock splits and reverse splits, the number of shares and price are adjusted by the split factor, with no divisor change. Rights issues are treated similarly if non-dilutive, but dilutive issues (e.g., deep discount subscriptions) trigger divisor adjustments to reflect the theoretical ex-rights price. Ordinary dividends cause no adjustment, as the price drop is naturally reflected, while special dividends (treated as capital returns) prompt a divisor tweak to neutralize the impact.[20]Rebalancing and Review Process
The Straits Times Index undergoes quarterly reviews conducted by FTSE Russell in partnership with the Singapore Exchange, scheduled for March, June, September, and December each year (as per ground rules effective May 2025). These reviews evaluate the eligibility of securities from the FTSE ST All-Share Index universe based on market capitalization, liquidity, and other criteria to ensure the index reflects the performance of Singapore's largest and most tradable companies. While quarterly reviews primarily facilitate the inclusion of eligible initial public offerings (IPOs), full constituent rebalances occur semi-annually in March and September, with all changes implemented after the close of business on the third Friday and taking effect at the start of trading on the following Monday.[18][9][21] Rebalancing ranks eligible securities by full market capitalization, selecting the top 30 that meet inclusion standards. To prevent excessive turnover and promote stability, buffer rules require a security to rank at the 20th position or higher for potential addition and at the 41st position or lower for potential deletion; this demands consistent eligibility over at least two consecutive quarters, avoiding frequent inclusions or exclusions based on short-term fluctuations. Weightings are based on free float-adjusted market capitalization, with automatic adjustments for IPOs—where qualifying new listings can enter after a minimum of five trading days if they represent at least 2% of the FTSE ST All-Share Index's full market cap, at least 15% of their shares are investable, and they meet liquidity thresholds—and for delistings, which prompt immediate replacement from a reserve list of pre-qualified securities.[18] Following the 2008 global financial crisis and the subsequent index revamp, liquidity thresholds were introduced to enhance tradability, requiring candidate securities to trade at least 0.10% of their shares in issue (after the application of any investability weightings) in each of at least 10 of the preceding 12 months. Existing constituents must maintain a turnover of at least 0.08% of shares in issue in eight of the preceding 12 months; these standards were strengthened in 2015 by increasing the threshold from 0.04% to 0.08% to address evolving market dynamics. Review outcomes are announced after market close on the first Friday of the review month, providing roughly two weeks' notice before implementation.[18][22][5] Special cases, such as mergers, acquisitions, or regulatory changes, trigger ad-hoc reviews outside the standard schedule to maintain index integrity; for instance, in the 2020s, such processes enabled inclusions from the technology sector amid shifts in market composition and listing rules.[18]Performance
Record Values
The Straits Times Index (STI) achieved its all-time closing high of 4,575.91 on 13 November 2025, accompanied by an intraday peak of 4,575.91 on the same date.[23] This milestone reflected robust market sentiment amid favorable economic conditions in Singapore. The index's historical lows are tied to major global events. During the 1987 Black Monday crash, the STI fell to approximately 1,223 points.[24] In the 1997 Asian financial crisis, it dropped to around 800 points, with a recorded low of 856.43 by September 1998.[25] The 2003 SARS outbreak saw the index reach 1,231.77 in March.[26][27] The 2008 global financial crisis pushed it to roughly 1,500 points in October.[28] Key milestones include the STI surpassing 3,000 points for the first time on 8 October 2013, closing at 3,025.96.[29] During the 2020 COVID-19 crash, it hit a low of 2,208 on 23 March 2020.[27] Post-recovery highs emerged in 2021 and 2022, reaching 3,123.68 and 3,251.33 respectively, supported by global stimulus measures.[30] The 2025 peak was propelled by strong performances in the technology and finance sectors, including banks and semiconductor firms, amid investor rotation toward stable markets.[31][32]Historical Annual Returns
The historical annual returns of the Straits Times Index (STI) reflect Singapore's integration into global markets, with performance driven by economic growth, regional crises, and international events. Price returns measure the change in index levels excluding dividends, while total returns incorporate reinvested dividends, typically boosting returns by 3-4% annually on average due to the dividend yields of constituent companies. Data for price returns from 1988 to 2024 are compiled from financial records, showing a long-term annualized price return of approximately 5%, with total returns estimated at 8-9% over the same period when dividends are included.[33][9] To illustrate the difference between price and total returns, the table below presents annual performance for 2015-2024, sourced from FTSE Russell for total returns in Singapore dollars and cross-verified with price return data. These years capture recent volatility, including the COVID-19 downturn and subsequent recovery.| Year | Price Return (%) | Total Return (%) |
|---|---|---|
| 2015 | -14.34 | -11.2 |
| 2016 | -0.07 | 3.8 |
| 2017 | 18.13 | 22.1 |
| 2018 | -9.82 | -6.4 |
| 2019 | 5.02 | 9.4 |
| 2020 | -11.76 | -8.1 |
| 2021 | 9.84 | 13.6 |
| 2022 | 4.09 | 8.4 |
| 2023 | -0.34 | 4.8 |
| 2024 | 16.89 | 23.5 |
Constituents
Selection Criteria
The selection criteria for constituents of the Straits Times Index (STI) are governed by FTSE Russell ground rules, focusing on size, liquidity, and investability to capture the performance of Singapore's largest and most tradable companies listed on the Singapore Exchange (SGX). Eligible securities must be ordinary shares or depository receipts from the FTSE ST All-Share Index universe, specifically those listed on the SGX Mainboard, while excluding investment trusts (under Industry Classification Benchmark subsector 30204000 Closed End Investments), non-equity investment vehicles (subsector 30205000 Open End and Miscellaneous Investment Vehicles), convertible preference shares, loan stocks, and any securities placed on the SGX Watch-List.[18] Companies are ranked primarily by full market capitalization, with the top 30 forming the index; a potential new entrant must rank at the 20th position or higher for inclusion, while those ranking 41st or lower face deletion at the next review. Secondary considerations include free-float adjusted market capitalization, where a minimum free float of more than 15% is required—companies below this threshold are excluded to ensure broad investor access—and a tertiary liquidity score based on median daily trading volume. Liquidity thresholds mandate that new candidates achieve at least 0.10% turnover of shares in issue (after investability weightings) over 10 of the preceding 12 months, while existing constituents must sustain 0.08% over 8 of 12 months, with tests conducted semi-annually in March and September; suspensions from trading are disregarded in these calculations.[18] Exclusion rules further enforce quality and stability: Watch-List securities are removed immediately at the next quarterly review and ineligible for 12 months thereafter, and any constituent failing liquidity or free-float tests is deleted until the subsequent semi-annual review. These criteria align with FTSE Russell's global standards, including the IOSCO Principles for Financial Benchmarks, to promote transparency and replicability.[18] Since FTSE Russell assumed management in 2008 through a partnership with SGX and Singapore Press Holdings, the criteria have shifted emphasis toward rigorous liquidity screening and free-float adjustments, reducing the constituent count from 47 to 30 and enhancing the index's role as a benchmark for Singapore's investable market; prior to this revamp, selection was looser, with greater weight on industrial sectors and minimal liquidity mandates.[7][15]Current Constituents
The Straits Times Index (STI) comprises 30 major companies listed on the Singapore Exchange (SGX), weighted by free-float adjusted market capitalization to reflect their economic significance. As of the September 2025 quarterly review, there were no changes to the constituents, preserving the composition set after the June 2025 quarterly review. This roster emphasizes Singapore's strengths in finance and real estate while incorporating industrials, transportation, and telecommunications for balanced representation.[35] The financial sector holds the largest allocation at 54.02%, driven by major banks, followed by real estate at 16.05%, industrials at 9.67%, telecommunications at 7.96%, utilities at 4.78%, consumer discretionary at 4.03%, consumer staples at 2.55%, and technology at 0.95%. This breakdown highlights the index's focus on stable, high-capitalization sectors that dominate Singapore's market, with the overall STI representing approximately 89% of the SGX's total net market capitalization of SGD 457.9 billion. International exposure is enhanced through constituents like Jardine Matheson Holdings and Hongkong Land Holdings, which operate globally despite SGX listings.[3][9] The top five constituents account for roughly 57% of the index weight, with DBS Group Holdings leading at 26.00%, followed by Oversea-Chinese Banking Corporation at 14.05%, United Overseas Bank at 9.89%, Singapore Telecommunications at 7.84%, and Jardine Matheson Holdings at 3.54%; these caps on over-concentration are managed through periodic reviews to maintain diversification. The full list of constituents as of November 2025, including sectors and approximate market capitalizations (in USD billions), is presented below. Recent inclusions in the 2020s, such as industrial and shipbuilding firms like Yangzijiang Shipbuilding, have added depth to non-financial sectors, though no modifications occurred in the March 2025 review.[3][1]| Symbol | Company Name | Sector | Market Cap (USD Bn) |
|---|---|---|---|
| D05 | DBS Group Holdings Ltd | Financials | 119.74 |
| O39 | Oversea-Chinese Banking Corporation Ltd | Financials | 61.37 |
| Z74 | Singapore Telecommunications Ltd | Telecommunications | 58.69 |
| U11 | United Overseas Bank Ltd | Financials | 43.08 |
| S63 | Singapore Technologies Engineering Ltd | Industrials | 19.84 |
| J36 | Jardine Matheson Holdings Ltd | Industrials | 18.44 |
| C6L | Singapore Airlines Ltd | Industrials/Transport | 15.80 |
| F34 | Wilmar International Ltd | Consumer Staples | 15.73 |
| S68 | Singapore Exchange Ltd | Financials | 13.83 |
| BN4 | Keppel Ltd | Utilities | 13.67 |
| C38U | CapitaLand Integrated Commercial Trust | Real Estate | 13.56 |
| H78 | Hongkong Land Holdings Ltd | Real Estate | 13.11 |
| 9CI | CapitaLand Investment Ltd | Real Estate | 10.54 |
| BS6 | Yangzijiang Shipbuilding Holdings Ltd | Industrials | 10.22 |
| A17U | CapitaLand Ascendas REIT | Real Estate | 10.02 |
| Y92 | Thai Beverage Public Co Ltd | Consumer Staples | 9.17 |
| U96 | Sembcorp Industries Ltd | Utilities | 8.68 |
| G13 | Genting Singapore Ltd | Consumer Discretionary | 6.90 |
| N2IU | Mapletree Pan Asia Commercial Trust | Real Estate | 5.92 |
| 5E2 | Seatrium Ltd | Industrials | 5.61 |
| U14 | UOL Group Ltd | Real Estate | 5.28 |
| M44U | Mapletree Logistics Trust | Real Estate | 5.12 |
| C09 | City Developments Ltd | Real Estate | 4.95 |
| D01 | DFI Retail Group Holdings Ltd | Consumer Discretionary | 4.52 |
| AJBU | Keppel DC REIT | Real Estate | 4.49 |
| ME8U | Mapletree Industrial Trust | Real Estate | 4.45 |
| S58 | SATS Ltd | Industrials/Transport | 3.96 |
| J69U | Frasers Centrepoint Trust | Real Estate | 3.56 |
| V03 | Venture Corporation Ltd | Technology | 3.32 |
| BUOU | Frasers Logistics & Commercial Trust | Real Estate | 2.76 |