A decrease in the dollar rate that started on the Unified Trading Session (ETS) today is due to high interest rates for credits in rubles, currency dealers said in an interview with RBC. They underlined that a substantial increase in ruble credit rates for 'today' deals on the inter-bank market had begun yesterday afternoon. As a result, the trade on October 15, the first business day of the week, closed at the level of 20-23%. The experts pointed out that in the morning on the second business day of the week, October 16, the interest rates for one-day ruble credits on the inter-bank market reached 30%. After that, this level somewhat lowered, and the rates for one-day ruble credits on the inter-bank market were 18-21% as of 11 a.m. on Tuesday, the experts reported. They found it hard to give a reason for the so obvious deficit of ruble liquidity of commercial banks at the beginning of this week. The dealers assumed that this is possibly due to tax payments to the budget and other payments to be made by banks. The experts definitely linked the decline of the weight-average dollar rate at today's morning trading session with the substantial lack of rubles at commercial banks.