DHI Group Inc.'s stock rocketed 26% in afternoon trade Tuesday, toward a seven-month closing high, after the employment connections services provider disclosed that hedge fund TCS Capital Management LLC had acquired a large stake in the DHI and expressed interest in a cash buyout. In an SEC filing late Friday, TCS said it owned about 5 million shares, or 9.7% of DHI's shares outstanding, as they were "undervalued" and represented an "attractive investment opportunity."