New ‘Up-tick’ Rule Introduced for Short Selling on Borsa İstanbul BIST 50
Borsa İstanbul, the Turkish stock exchange, has announced the introduction of a new regulation that will affect the short selling of shares included in the BIST 50 index.
Effective as of today, Tuesday, 22 September 2026, an ' up-tick rule' (yukarı adım kuralı) will be applied to all short selling transactions for shares eligible for shorting within this index. The decision follows directly from a directive issued by Turkey’s Capital Markets Board (Sermaye Piyasası Kurulu – SPK).
This change represents a significant measure intended to regulate the market and potentially influence investor behaviour concerning the 50 largest companies listed on the Turkish exchange. Understanding the up-tick rule and short selling is essential, as short selling is an investment strategy where investors borrow shares they do not own, sell them on the market, and hope to repurchase them at a lower price later.
This allows them to return the shares to the lender and profit from the price decline.
This strategy is frequently utilised by investors who anticipate that a stock' s price will fall. However, uncontrolled short selling can contribute to reinforcing downward price trends and creating increased market volatility.
An ' up-tick rule' stipulates that a short selling transaction can only be executed at a price higher than the last traded price, or at the current market price if that price is higher than the previous closing price. The objective is to prevent short sellers from driving stock prices further down during a decline by ensuring that short selling only occurs when the stock exhibits a positive price movement.
This is a tool frequently employed by regulatory authorities to maintain market stability and provide protection against aggressive speculative attacks. The introduction of the up-tick rule on the BIST 50 index is expected to have several implications for the Turkish capital market.
Primarily, it may contribute to reducing volatility in the largest and most actively traded shares, which could lead to a more stable and predictable investment environment.
This is particularly relevant during periods of economic uncertainty, when market participants seek security. The regulation may also impact the strategies of short sellers and reduce the immediate effect of bearish sentiment.
By making it more difficult to short stocks aggressively, the measure may help to support share prices and protect against sudden, sharp drops.
For both domestic and international investors trading on Borsa İstanbul, this requires an adjustment in risk management and trading strategies, particularly for those who rely on short selling within BIST 50 companies.
It also highlights the role of the SPK as an active regulator in the Turkish financial system, which continuously assesses and adjusts market rules to promote orderly and fair markets.
Source: Haberglobal
