July 2026 data from the Central Securities Depository (MKK) show that the investor structure of Borsa Istanbul has a striking dual character. On one side are retail investors, counted in the millions; on the other are large investors, extremely few in number yet managing a far larger stock of capital. According to MKK, in listed equities the portfolio value of retail investors is about TRY 2.90 trillion and their number about 6.88 million. Large investors’ portfolio value is about TRY 6.32 trillion, while their number is only 14,766 (MKK, 2026a). The picture is that the number of investors in Borsa Istanbul has risen, but capital has not been spread across the base to the same degree.
A large investor in these figures does not represent a single natural person: investment funds, pension funds and similar collective vehicles can pool the savings of many individuals into a single institutional portfolio. The asymmetry can therefore also be read as a measure of how far capital is concentrated in professional and collective investment vehicles.
Key Indicators
| Indicator | Retail investors | Large investors |
|---|---|---|
| Listed-equity portfolio | TRY 2.90 trillion | TRY 6.32 trillion |
| Number of investors | 6.88 million | 14,766 |
| Share of portfolio value | 31.5% | 68.5% |
| Share of investor count | 99.8% | 0.2% |
| Average balance per investor | TRY 422 thousand | TRY 428 million |
Note: Ratios and averages are calculated from MKK’s rounded trillion-lira figures, so small differences may arise.
The Scale of Investor Asymmetry on BIST
Taken together, about 68.5% of the listed-equity portfolio is held by large investors and 31.5% by retail investors. In the investor count, by contrast, retail investors account for about 99.8% and large investors for only 0.2%. In other words, large investors that make up two-tenths of one per cent of investors hold about 68.5% of the listed-equity portfolio, while retail investors who make up 99.8% of investors hold 31.5% of that portfolio. Put differently, there is roughly one large investor for every 466 retail investors. The average listed-equity portfolio is about TRY 422 thousand per retail investor and about TRY 428 million per large investor. The average large-investor portfolio is thus about 1,015 times the average retail portfolio.
What This Means for the Market Mechanism
The gap shows that a simple comparison of investor numbers is not enough to explain the market’s economic structure. In financial markets, prices are not formed on a one-person-one-vote basis. An investor’s potential effect on price is related to order size, trading frequency, the liquidity of the portfolio, market depth and the scale of position changes. The numerical majority of millions of retail investors therefore does not imply a matching stock of capital or pricing power. In large, highly liquid companies in particular, portfolio-rebalancing trades by large funds can have a marked effect on prices and turnover. In thinner, smaller-cap stocks, by contrast, a large number of retail investors moving in the same direction can also strengthen short-term price pressure. The weight of large investors in the stock of capital and retail influence in daily trading dynamics should therefore be kept distinct. For Borsa Istanbul, the MKK data also point to a structural fact: the investor base is retail, while the capital base is distinctly concentrated among large investors.
Large Investors and Market Efficiency
The weight of large investors does not come only from the larger portfolios they carry. Professional research teams, data infrastructure, portfolio optimisation, risk-management systems, access to derivatives and more disciplined investment processes increase large investors’ capacity to produce information and to incorporate it into prices. Higher ownership by large investors therefore has the potential to raise price efficiency by inducing information-based trading. The weight of large investors does not, however, always mean more stable price formation. When large investors respond in the same direction to similar signals, benchmarks or risk limits, collective moves can be amplified.
Academic studies show that large investors can follow one another’s trades and that institutional herding can emerge (Fan et al., 2024; Tekel & Şendeniz-Yüncü, 2024; Gu et al., 2026).
The Position of the Retail Investor
Retail investors have a different set of advantages and risks. A smaller portfolio allows the retail investor to change position with less market impact and, in some smaller companies, to move more flexibly. A large literature on retail behaviour, however, shows that overtrading, limited diversification, attention effects and behavioural biases can impair performance. The asymmetry on Borsa Istanbul should therefore be assessed not only in terms of the size of capital, but also in terms of information-processing capacity and decision processes.
The time dimension is also noteworthy. In July 2025 the listed-equity portfolio of retail investors was about TRY 2.13 trillion and that of large investors about TRY 4.85 trillion. In the same period the number of retail investors was about 6.40 million and the number of large investors 13,432 (MKK, 2026a). Calculated from the rounded figures, the large-investor share of the portfolio has eased from about 69.5% to 68.5%, and the gap in average portfolio size from about 1,085 times to 1,015 times. The change shows that the asymmetry has narrowed only modestly over the past year.
Conclusion
On the July 2026 data, the following may be said of Borsa Istanbul: participation has become mass, but capital power has become concentrated. About 6.88 million retail investors make up almost all of BIST’s investors, while only 14,766 large investors hold more than two-thirds of the listed-equity portfolio. The investor structure of Borsa Istanbul can therefore be summarised as “numerical majority with retail investors, capital majority with large investors.”
The most striking message of the MKK data is that Borsa Istanbul is a two-layered market: a wide retail participation base, with a strong weight of large investors in the stock of capital. Once the largest portfolios are taken to represent large investors, Doğan and Sayılgan (2025) add an important second finding: there is also asymmetry among retail investors themselves, in number, portfolio size and market function. Lower-value portfolio groups stand out more for liquidity, while the participation of higher-value portfolio groups shows a stronger positive association with market returns. Borsa Istanbul should therefore be read in three dimensions: investor count, the stock of capital, and trading/pricing behaviour.
Doğan and Sayılgan (2025) also show that lower-portfolio retail investors contribute more to market liquidity while displaying a negative or weak association with market returns, whereas higher-portfolio investors are more strongly and positively related to market returns.
References
- Doğan, Y., & Sayılgan, G. (2025). The Effect of Local Participation on Market Pricing and Liquidity: Evidence from an Emerging Market. Universal Journal of Accounting and Finance, 13(2), 49–60. https://doi.org/10.13189/ujaf.2025.130201
- Fan, Y., Song, Q., Guan, R., Ly, K. C., & Jiang, Y. (2024). Mutual fund herding and performance: Evidence from China. International Review of Financial Analysis, 95, 103503. https://doi.org/10.1016/j.irfa.2024.103503
- Gu, C., Guo, X., & Hibbert, A. M. (2026). Institutional herding, credit rating and overreaction in stock price. Journal of Financial Research. Advance online publication. https://doi.org/10.1111/jfir.70057
- Merkezi Kayıt Kuruluşu (MKK). (2026a). MKK Monthly Market Bulletin: July 2026. https://www.mkk.com.tr/sites/default/files/2026-08/MKK-Aylik-Piyasa-Bulteni-Temmuz-2026.pdf
- Merkezi Kayıt Kuruluşu (MKK). (2026b). MKK Market Data, 2 August 2026. https://www.mkk.com.tr/
- Tekel, O., & Şendeniz-Yüncü, İ. (2024). Mutual fund herding in industries: The Turkish case. Emerging Markets Finance and Trade, 60(12), 2850–2867. https://doi.org/10.1080/1540496X.2024.2331007
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