Euro zone preparation for a possible Greek currency exit sent U.S. markets into a dive Wednesday that was largely reversed in afternoon trading. The Dow dropped 1 percent to its lowest level of the year before recovering to close at 12,472, down a quarter of a percent. The S&P 500 and Nasdaq, which traded in the red for most of the day, recovered and closed up 0.06 percent and up 0.23 percent respectively. In Europe, leaders meeting to discuss the Greek crisis agreed that each euro zone member should formulate a contingency plan in case Greece leaves the currency bloc, rattling investors. The announcement also tugged on oil and other commodities. Oil futures fell below $90 a barrel for the first time in nearly seven months, with July prices hitting a session low of $89.55. Facebook, however, rebounded and closed in the green (up 3.23 percent at $32 a share) for the first time since its botched IPO Friday.