Hold or sell REGI?

Hi

So at the beginning of the week I invested in REGI since I considered it heavely undervalued. The stock has risen sharply since (73% from my buy price). I no longer consider it undervalued at this prices. The stock rose because of a proposal to acquire the company for 3B, this values the company at 61$ a share. Should I sell everything at current prices (approx 58.5$) or wait for the acquisition and profit 61$ per share?

Thanks!
Daniel