Secret IRS records reveal dozens of highly fortuitous biotech and health care trades. One executive bought shares in a corporate partner just before a sale, and an investor traded options right before a company’s revenues took off, netting millions.

Owners like Steve Ballmer can take the kinds of deductions on team assets — everything from media deals to player contracts — that industrialists take on factory equipment. That helps them pay lower tax rates than players and even stadium workers.

ProPublica found landlords in at least four states have violated the ban, which was put in place by the CARES Act but has no clear enforcement mechanism.