BP settled claims with Gulf residents over the 2010 oil spill for $7.8B this weekend. The WSJ is reporting that this settlement plus others yet to come with the justice department puts the final cost to BP likely somewhere in the $40B range.
Compare this result to the initial loss in market cap to BP in 2010. The company went from a $178B company to a $90B company at the height of the selloff. This implies that some were estimating that the cost to BP could be $90B, more than twice what it will likely end up being.