edit : also it's probable the same coins are being traded many times, boosting the volume.
say the (fair) start price is 200 - you buy 80 BCC for 16-18k which rises the price to 300
then others see the price is rising and are urged to buy "while it's cheap", which rises the price to 500 for another 5-10k (but that's not your money anymore ), because there are just 20 left
then you sell 50 for 400 (you got 2-4k already), but others are selling too because "the price falls I loose!!!", so you can buy again lower than that and the liquidity is even lower (you kept some 30 away) ...
the next step is 300/700 and so on while the amounts are limited to those 100, but when the exchange opens for deposits and withdrawals you sell all because the price will quickly go even lower than those initial 200