SAINT PETERS, MO. ( TheStreet) -- MEMC Electronic Materials ( WFR), the U.S. semiconductor and solar materials company that has been trending up throughout March trading, hit a share price at the close on Tuesday of $15.51, MEMC's highest closing price since October 2009. MEMC has the biggest gain in the S&P 500, climbing 5.7% to the $15.51 close on Tuesday. Call-option trading increased on rumors that MEMC would be acquired, a rumor repeated by Bloomberg in its Tuesday market report. Shares volume for MEMC was twice its average volume. On Wednesday morning, Wunderlich Securities analyst Theodore Kaufman was out with a note saying the latest acquisition rumors swirling around MEMC Electronic Materials are not well-grounded. While the solar sector rallied significantly on Friday and Monday on more bullish 2010 demand calls from the Street, MEMC is the only of the solar stocks to have steadily increased in price throughout the previous month, rising from a share price of below $13 at the outset of March. MEMC shares were down slightly in early morning trading on Wednesday, just after the opening bell. Wunderlich has a hold rating and a $15 target price on MEMC. The Wunderlich analyst wrote that this type of trading activity in MEMC shares has sparked speculation of a takeover on Jan. 6, 2010; Nov. 3, 2009; Sept. 16, 2009; and Mar. 30, 2009. Wunderlich's O'Neill finds it difficult to see the value in an MEMC takeover as long as margins are falling and product is in worldwide oversupply, which is the analyst's current view of the semiconductor and solar market. "These segments are under pricing pressure from too much competition and lack of commercial credit, or, in the case of the legacy semiconductor industry, are growing at an increasingly slow rate," the Wunderlich analyst wrote.