GoPro (GPRO 13.88%) stock is posting massive gains in Wednesday's trading. The action-camera specialist's share price was up 23% as of 12:45 p.m. ET and had been up as much as 73% earlier in the session.Despite the huge rally for the stock, there's not any business-specific news pushing GoPro's valuation higher today. Instead, the company has recently gained favor as a meme-stock play -- and some investors are buying up shares in hopes of scoring big returns in a short period of time. GoPro surges on meme- ...