Large wicks in liquidity zones mean that institutions/banks are luring retail traders into either selling so they can buy or vice versa. On EUR/USD we can see a massive wick to the downside luring traders into selling so the big players can buy into those positions, propping up the price as their end goal.
I always advocate the only way to trade FX and any other major markets is to see clues left behind and try and ride the wave of whatever the institutions are trying to do.