Another biotech stock whose insiders are doing some big buying in is Opko Health ( OPK), which is focused on developing a range of solutions, including molecular diagnostics tests, pharmaceuticals and vaccines. Opko operates in two segments: pharmaceutical and instrumentation segments. Insiders are paying up here to own shares of this name since the stock is up over 10% so far in 2011. Opko Health has a market cap of $1.2 billion and an enterprise value of $1.1 billion. This company is currently not profitable yet. Its operating cash flow is -$21.1 million, and its levered free cash flow is -$22 million. Opko is cash-rich, however, with $107.86 million in cash on its books and just $14.55 million in debt. After you back out the debt, that gives the company $93.31 million in cash. The CEO, chairman of the board and director just bought 100,000 shares, or $412,064 worth of stock, at $4.12 per share. This same CEO has been steadily buying millions worth of OPK stock since 2010. It's hard to make a bearish case against a stock where the CEO has been buying up shares as consistently as at OPK. From a technical standpoint, this stock is trading above both its 50-day and 200-day moving averages, which is bullish. The stock has also been making higher lows and higher highs since the middle of June, which shows that the trend is positive. If you're looking to get long OPK, I would wait until the stock breaks out above some near-term overhead resistance at around $4.40 to $4.50 a share. I would then add aggressively to any long position if you see OPK trigger a major breakout above $5.03 a share on solid volume. Look for a volume move that registers close to or over the three-month average action of 988,000 shares. Another way to play this name would be to buy it on any weakness as long as it holds above its 50-day ($3.83) and 200-day ($3.72) moving averages. It's worth mentioning that OPK has a decent amount of short-sellers involved in the stock. The current short interest as a percentage of the float for OPK stands at 8%. If you see this stock break out, then expect a sharp short-covering rally to ensue as the bears peel off some of their bets.