BIST Imposes Short‑Sell Ban on Cem Zeytin and BJKAS Shares Under Volatility‑Based Measures

On the Borsa Istanbul, under the Volatility‑Based Measures System (VBTS), the exchange has prohibited short‑selling and leveraged trades on Cem Zeytin (CEMZY) and Beşiktaş Futbol Yatırımları Sanayi ve Ticaret A.Ş. (BJKAS) shares until 18 September 2026.

BIST’s Volatility Clamp‑Down

The Securities Market Board’s (SPK) decision, anchored in the VBTS framework, bars short‑selling and leveraged positions on the two stocks from 21 August 2026 through to 18 September 2026, covering the entire trading session.

18‑Day Freeze Details

■CEMZY and BJKAS cannot be short‑sold or traded on margin for 18 days.

■The restriction applies from session start to session end.

■It is a precautionary measure against rising volatility and market imbalance.

Market Sentiment Shift

■On the first trading days, the stocks experienced a 2–3% price swing.

■Liquidity fell ≈15% due to curtailed short‑selling activity.

■Traders recalibrated their short‑sell strategies.

Strategic Implications for Investors

■Portfolio managers moved risk‑off by diversifying into other asset classes.

■Arbitrage opportunities expanded during the high‑volatility window.

■The temporary nature of the ban reshaped expectations about future market stability.

BIST’s targeted restriction signals a broader regulatory tightening around high‑beta equities, nudging market participants toward more conservative, long‑term positions while safeguarding liquidity.