As if deciding how to invest 401(k) money isn't perplexing enough, we soon could be staring down some ridiculously overwhelming new options — including whether to buy bitcoin or turn to private equity as a way to juice up retirement returns. The U.S. Securities and Exchange Commission, the Labor Department and the Treasury are tasked now with working out regulatory details for paving the way for alternative investments, including cryptocurrency, to be offered in 401(k) plans. Ultimately, 401(k) investors ...