NEW YORK ( TheStreet) -- Big bank stocks can't catch a break. After outperforming the broader markets in the first quarter of the year, the sector has erased most of those gains since April. Investors appear to have run out of reasons to buy bank stocks, with valuations no longer a steal and macro factors taking a turn for the worse. JPMorgan Chase's ( JPM) unexpected disclosure of
its $2 billion trading loss has also scared away already weary bank stock investors. JPMorgan had enjoyed a premium as a "safe haven" asset, having demonstrated prudent risk management and leadership through the crisis. But the recent lapse in risk management has delivered a black mark to its reputation. The lack of near-term catalysts combined with expectations of another weak summer is also weighing on sentiment. Earlier in the year, expectations of the nationwide mortgage settlement, higher deal activity thanks to Capital One's ( COF) acquisition spree, and the Fed's stress tests all helped to push bank stocks higher. But the catalysts are now switching to more "macro factors" according to Barclays Capital analysts. Bank stocks stand to gain from higher interest rates, more robust loan growth and sustained improvement in home prices as well as lower headline risk from Europe, according to analyst Jason Goldberg. But the timing of these events remains highly uncertain. JMP Securities analyst David Trone recently took an ax to the estimates and price targets of the big banks. "We now expect the shares and earnings of our bulge-bracket names to fall significantly over the balance of 2012 due to a confluence of material events, both at home and abroad, led by an increasingly troublesome situation in Europe," he wrote in a recent note. According to Trone, the U.S. has a "trifecta of worries" including the fiscal cliff, the expiration of market-related tax cuts and Presidential elections. More regulation is also on the cards with calls to toughen the Volcker rule and break up big banks resurgacing following the recent trading fiasco at JPMorgan. Morgan Stanley's ( MS) Facebook ( FB) IPO flub is also raising questions among regulators. "Washington's policy response to the losses of '07-'09 was already tough, but now the JPM episode has caused a new flare-up of emotions, thus final Volcker rules are likely to be painful," Trone wrote. Here's a look at the five stocks that have taken the biggest hit over the past month amid a litany of negative headlines. Only stocks with a market capitalization of greater than $1 billion have been considered.