MicroStrategy shares have gained more than 400% since the start of the year thanks to investor optimism about the software company's strategy of buying bitcoin as the cryptocurrency repeatedly hits record highs.

Regulation of cryptocurrency will relax — sending bitcoin's price up. Investors could profit as MicroStrategy sells stock to buy more appreciating bitcoin.

MicroStrategy stock is trading way above the value of its huge bitcoin stash. That is just the latest example of market valuations that break "the law of one price", writes Heard on the Street's Jonathan Weil.