One earnings short-squeeze candidate in the biotechnology and drugs complex is Optimer Pharmaceuticals ( OPTR), which is set to release numbers on Thursday after the market close. This company is focused on discovering, developing and commercializing hospital specialty products. Wall Street analysts, on average, expect Optimer Pharmaceuticals to report revenue of $28.77 million on a loss of 38 cents per share. If you're looking for one stock that's held up relatively well during the recent market weakness and seen strong upside volume flows, then make sure to take a strong look at shares of Optimer Pharmaceuticals. The current short interest as a percentage of the float for Optimer Pharmaceuticals is very high at 21.4%. That means that out of the 45.36 million shares in the tradable float, 9.88 million are sold short by the bears. The bears have also been increasing their bets from the last reporting period by 15.3%, or by about 1.3 million shares. From a technical perspective, OPTR is currently trading above both its 50-day and 200-day moving averages, which is bullish. This stock sold off hard in early April from around $14 to a low of $11.87 a share on monster volume. Following that move lower, shares of OTPR have rebounded sharply towards its current price of $14.77 a share. That move now puts OPTR within range of triggering a major breakout trade post-earnings. If you're bullish on OPTR, I would look for long-biased trades after its report if this stock manages to break out above some major overhead resistance at $15.12 to $15.40 a share with high-volume. Look for volume on that move that registers near or well above its three-month average action of 645,698 shares. If we get that action, then OPTR should continue its uptrend momentum towards its 2011 high of $17.95 or possibly even $20 a share. I would simply avoid OPTR or look for short-biased trades if the stock fails to trigger that breakout, and then drops back below its 50-day moving average of $13.57 a share with heavy volume. If we get that action, target a move lower towards its 200-day moving average of $12.48 or possibly even $11 a share if the bears spark a big selloff post-earnings.