Last week saw dramatic moves in financial markets. Gold and silver, which rose very sharply last year and in January, suddenly lurched down before stabilizing. Bitcoin took a nosedive before achieving a significant, although partial, recovery on Friday. Mega-cap tech stocks posted huge earnings gains but announced even more lofty capital spending plans, contributing to a general selloff in the sector. And, at the end of the week, stocks saw a resounding rally, pushing the venerable Dow Jones Industrial Average over 50,000 for the first time ever.