London Fix (4PM Fix)

The London Fix (WM/Reuters fix) is the reference exchange rate struck each weekday around 16:00 London time by averaging trades and quotes over a five-minute window. Index funds, corporates and banks use it to value portfolios, so enormous orders cluster in that window, producing a brief volatility spike and wider spreads. After the 2013 manipulation scandal the window was widened from one minute to five.