The biggest buy by far in the second quarter was Apple ( AAPL). Renaissance picked up 714,490 shares of the technology giant, building a $283 million stake in the firm at current price levels. RenTec isn't the only big institutional name that's been picking up shares of Apple lately. Last week, Carl Icahn announced that he'd taken on a massive billion-dollar stake in the Cupertino, California-based company. Icahn and Renaissance bought for very different reasons, but the end result is the same: they're both bullish on Apple this summer. >>4 Big Tech Stocks on Traders' Radars Apple sports a bargain valuation right now thanks to a major decline from the highs that the firm set last fall. Apple sports a price-to-earnings ratio of just 12 -- a modest multiple that reflects investors' belief that the firm can't continue the breakneck growth it's achieved in recent years. But back Apple's mammoth cash position out of the equation, and Apple's P/E drops flat to 7. There's a lot of attention on Apple's media event scheduled for Sept. 10. The potential for two new iPhone models as well as more speculative offers such as an Apple television and watch could provide a major catalyst for upside in Apple's sales. Meanwhile, the firm's Macintosh computer sales continue to crush the rest of the industry in terms of profitability and market share growth. With shares above $500 for the first time since January, the second half looks strong for this $458 billion tech stock.