The Securities and Exchange Commission (SEC) is reportedly investigating whether stock sales by Tesla CEO Elon Musk and his brother, Kimbal Musk, violated insider-trading rules.

Launched in 2021, the probe is looking into shares sold by Kimbal valued at $108 million one day before Elon polled Twitter to see whether or not he should offload 10 percent of his stake in the company, suggesting he would run with the results. Though the tweet itself was a snide way of discussing proposals from Democrat legislators that would have imposed new taxes on unrealized capital gains, effectively money that doesn’t yet (and may never) exist.