BENGALURU (REUTERS) - GameStop has raised US$551 million (S$730.4 million) through an equity offering as the videogame retailer accelerates its shift to e-commerce, sending its shares 15 per cent higher in extended trading on Monday (April 26). Based on Reuters calculation, the average price of the shares sold was US$157.43. The company's stock has gained more than 850 per cent this year thanks to a push by retail investors to drive up prices of heavily shorted stocks. GameStop said earlier this month George Sherman will step down as its chief executive officer in the biggest management shakeup at the retailer, giving top shareholder Ryan Cohen more control.