You misremember. On Jan 23-24, there is a 36 hour period where it jumped from $16.8 to $19.2. http://bitcoincharts.com/charts/mtgoxUSD#rg30zczsg2013-01-24zeg20

You misremember. On Jan 23-24, there is a 36 hour period where it jumped from $16.8 to $19.2. http://bitcoincharts.com/charts/mtgoxUSD#rg30zczsg2013-01-24zeg2013-01-25ztgSzm1g10zm2g25zv http://bitcoincharts.com/charts/mtgoxUSD#rg30zczsg2013-01-24... That's the closest scenario I can find. Certaintly not "$15.5 to $20+ in 12 hours".