That's 8:30am EST right?
Yep, from Briefing.com:
"Ms. Yellen's prepared remarks will be released at 8:30 ET while the subsequent Q&A session is expected to receive significant attention since it will be the first public appearance for the new Chair of the Federal Reserve."
Again, this could be a nothing moment or could add momentum in any direction. Hard to predict what she will say, but I don't have any reason to believe she intends to drop a bomb on the market, and expect fairly measured and predictable behavior in line with current Fed policy trends. If the market hates what she says, look for shorts to pounce with trading bots set to kill and negative linkbait articles firing off fast. But I don't think they have enough ammunition to stop the short squeeze happening completely.
If for some reason the market loves her tomorrow and the NASDAQ is pushing up hard as a result, then that could be a catalyst that, combined with today's catalysts, propels TSLA up faster than a SpaceX rocket, and $200 could be long gone.