Both BTC and XMR hit psychological milestones ($10k BTC, $200 XMR). When that happened, lots of people who had been telling themselves, "When this hits $10k/$200, I'll sell."

This created a flood of supply which pushed both prices back down. Then the supply was snatched up, the prices rose again, and the people who thought about selling at $10k/$200 but didn't the first time went ahead and sold the 2nd/3rd brief time both coins hit those levels. I think we'll see more of that over the next few days.

In both cases, lots of news was generated which will help with demand. I expect both to go sideways around $10k/$200 and then go above those levels as more people enter the markets. Plus, Monero has Globee and 2/3 multisig in mid-to-late testing, and when people start using those, demand will increase even more.

Good times!