# Borsa Istanbul volatility and fund investigation > Live situation record from CLSTR: https://clstr.news/situations/borsa-istanbul-market-volatility > Updated: 2026-10-21T21:53:00.000Z. Sources: 33. Developments: 4. The Borsa Istanbul BIST 100 index experienced volatility in early October 2026, driven largely by the trading activities of Bank of America (BofA) clients. After a brief recovery on October 13, the index faced downward pressure, recently closing at 12,118.29 points, representing a 1.08 percent loss. This decline was exacerbated by BofA customers contributing net sales totaling 1.95 billion TL, impacting stocks such as Akbank and Turkish Airlines. This volatility coincides with an ongoing investigation into investment funds, where authorities have placed assets under judicial control for 109 individuals following allegations of market manipulation and unfair gains. This follows the previous suspension of trading for 131 investment funds on the TEFAS platform, which caused shares like Özata Denizcilik and Destek Faktoring to drop 88 percent. Borsa İstanbul General Manager Korkmaz Enes Ergun clarified that the institution has fulfilled its regulatory duties by notifying the Capital Markets Board (SPK) regarding suspicious funds. However, allegations have surfaced claiming that 130 warnings issued by Borsa İstanbul were not acted upon by the SPK, a claim the regulator has denied, asserting that all notifications are “meticulously evaluated.” In response to security concerns, officials emphasized that Private Pension System (BES) assets are protected by a multi-layered audit network involving the SPK, SEDDK, Takasbank, and the Pension Monitoring Center (EGM). These measures ensure assets remain independent of insurance companies' balance sheets and cannot be seized or included in bankruptcy proceedings. Meanwhile, TCMB Governor Fatih Karahan noted at IMF and World Bank meetings that core inflation is slowing and preference for the Turkish Lira remains strong despite high energy prices. On October 21, the market trend continued downward as the BIST 100 index closed 1.8 percent lower at 11,577 points, with losses recorded across all sector indices. ## Claims - US inflation rose 0.6 percent monthly and 3.7 percent annually in September. (corroborated by 5 sources) - The BIST 100 index closed with a 1.08 percent daily loss at 12,118.29 points. (corroborated by 3 sources) - TCMB President Fatih Karahan noted that core inflation is slowing despite high energy prices. (corroborated by 3 sources) - The spot price of gold fell 1.80 percent to 4,079 dollars per ounce. (corroborated by 2 sources) - The spot price of silver dropped 5.71 percent to 55.79 dollars per ounce. (corroborated by 2 sources) - The US 10-year Treasury yield increased by 11 basis points to 5.33 percent. (corroborated by 2 sources) - Borsa İstanbul General Manager Korkmaz Enes Ergun stated that the institution has fulfilled its responsibility by making necessary notifications to the Capital Markets Board (SPK). (corroborated by 2 sources) - Gürol Sami Özer stated that BES fund assets are legally protected and cannot be seized or included in an insurance company's bankruptcy estate. (corroborated by 2 sources) - There were allegations that Borsa İstanbul had issued 130 warnings regarding suspicious investment funds since 2025. (corroborated by 2 sources) - The Capital Markets Board (SPK) stated that it meticulously evaluates all notifications from Borsa İstanbul and applies necessary sanctions. (corroborated by 2 sources) - Bank of America customers recorded net sales of 1.95 billion TL in Borsa Istanbul. (single source) - Ozata Denizcilik and Destek Faktoring shares dropped 88 percent over 20 trading days due to fund liquidations. (single source) ## Timeline ### 2026-10-21: Borsa İstanbul faces volatility amid geopolitical tensions and regulatory changes Borsa İstanbul faces market volatility driven by Middle East tensions and AI investment concerns, while new Turkish legislation regarding investment fund liquidation has been passed by the TBMM. 10 sources. https://clstr.news/cluster/borsa-istanbul-market-activity-and-corporate-developments ### 2026-10-13: Borsa İstanbul and US inflation data drive global market volatility US inflation data exceeding expectations has pressured global markets, while Borsa İstanbul faces scrutiny over investment fund notifications and volatility in the BIST 100 index. 28 sources. https://clstr.news/cluster/borsa-istanbul-experiences-fluctuating-volume-and-bank-of-america-buying ### 2026-10-06: Borsa İstanbul falls as Bank of America executes 1.8 billion TL in net sales Borsa İstanbul's BIST 100 fell 0.5% as Bank of America clients executed 1.8 billion TL in net sales, led by Tüpraş. Global markets remain focused on US Federal Reserve policy signals. 7 sources. https://clstr.news/cluster/borsa-istanbul-falls-as-bank-of-america-executes-18-billion-tl-in-net-sales ### 2026-10-04: Borsa Istanbul rises as Bank of America targets Akbank Borsa Istanbul's BIST 100 rose 1.4% as banking stocks led gains. Bank of America recorded net purchases of 545 million TL, with Akbank being the top acquisition following an HSBC price target update. 5 sources. https://clstr.news/cluster/borsa-istanbul-rises-as-bank-of-america-targets-akbank --- Cite as: Borsa Istanbul volatility and fund investigation. CLSTR, https://clstr.news/situations/borsa-istanbul-market-volatility