Quote from kiwi_trader:
When they are convinced that a bottom is in. They're worried about 5% or 10% days and the carnage it will reap on some traders and brokers.
Quote from Tums:
Interactive Brokers Bulletin Board
IMPORTANT NOTICE regarding Intraday Margin In light of the market volatility and the continuing turmoil in financial services stocks, IB will eliminate intraday margin reductions.