Usually CampBx Asks trails MtGox (i.e. if MtGox price is $10, CamBx is $9.
but I am observing the opposite since last few days.
Mt. Gox has been improving their speed for withdrawals, particularly USD withdrawals. Dwolla is still a week or so, but down from the two to three weeks. When international bank wire withdrawals took days to weeks to be sent, not as many people were willing to sell on Mt. Gox.
That has given sellers, particularly those whose intention is to sell at whatever is the current market price, the motivation to return to selling on Mt. Gox's BTC/USD market.
The flow of fiat funds still isn't fast enough to let the arbitrage tools run on autopilot so that's why there can be relatively large gaps between the exchange rate on one market versus the rate on another.
