Just look at what happened when GOX was failing and the GOXcoins were trading on bitcoinbuilders website.
Yep...total Goxcoin market was driven by bots, whilst bots trading on the solvent exchanges still responded to action on Gox. This meant that Karpeles could use Willy to drive the real Bitcoin market around, which I suspect he did. I suspect that Karpeles was the 10K whale who came to Stamp on eve of crash to $400 and tricked the bots on Stamp into eating into around 6K BTC worth of his 10K limit order, as the bot traders furiously bought Bitcoin due to Stamp being undervalued in comparison with BTC-e, Bitfinex, Huobi etc, which had corrected and then ramped due to Gox crashing and then ramping right up. Due to 10K Ask wall, Stamp got stuck some $30-$40 dollars beneath spot price of the other exchanges so the bots kept buying and buying into the 10K Ask wall at $579. Two days later, Bitcoin crashed down to $400.
I don't think it was so much "bots" that manulipiate the market but rather misinformation.
I remember there was so many forged IRC chat logs on reddit around when Gox suspended withdrawals but did not file for bankruptcy yet.