Strategy, the bitcoin accumulation firm founded by Michael Saylor, recorded a loss of nearly $13 billion in the first quarter as declining bitcoin prices continue to weigh on its digital-currency stash. Strategy’s first-quarter net loss widened to $12.77 billion, or $38.25 a share, compared with a loss of $4.23 billion, or $16.49 a share, a year earlier. In the most recent period, the company recorded an unrealized fair-value loss of $14.5 billion on its digital assets, complying with accounting rules that require companies to value their holdings at current market prices.