Would someone be able to explain to me what is the reason behind getting an error when placing a limit sell order on GDAX with the message 'insufficient funds".  This afternoon I was trying to cash out, selling BTC to EUR.  I set the limit order at just above the market rate, hit place order and then I got the message.  I was trying to sell 100% of my BTC which I thought might have been the issue so I reduced it by a bit to cover any fees but it still wouldn't go through.  I ended up having to sell BTC to my Coinbase EUR wallet and pay their exorbitant fee!!!  I'm new to GDAX and cc trading in general so I obviously did something wrong but I'd appreciate an explanation so I can avoid doing the same thing in future. Thanks in advance.