The BIST 100 index in Borsa Istanbul started the week with a 0.24% decline at 10,481.45 points. At the opening, the BIST 100 index fell to 10,481.45 points with a decrease of 25.65 points and 0.24% compared to the previous closing. The banking index gained 0.06% while the holding index increased by 0.45%. Among sector indices, the financial leasing factoring sector had the highest increase at 0.89%, while trade suffered the most significant loss at 3.16%. In the domestic market, Borsa Istanbul followed a buying-weighted trend on Friday, with the BIST 100 index closing the day at 10,507.11 points, gaining 0.46%. Globally, concerns about the exacerbation of trade wars due to US President Donald Trump’s protectionist trade policies and the possibility of a slowdown in the world’s largest economy, the US, have increased risk perception. On the other hand, in the Borsa Istanbul, it was decided to apply the upside tick rule in short selling transactions in shares listed in the BIST 50 Index for one trading day. Analysts noted that from a technical perspective, the support levels for the BIST 100 index are at 10,350 and 10,300 points, while the resistance levels are at 10,550 and 10,650.