All you need to do is initiate an ACATS transfer at your preferred receiving brokerage and your assets will transfer over in-kind, meaning that your stocks, bonds, mutual funds, etc will transfer and cost basis for tax purposes will transfer over as well.
All of the major brokers such as TD, Fidelity, Schwab, E*Trade, etc support ACAT transfers.
Note: proprietary or non-transferable positions may still need to be liquidated, but all publicly traded instruments should be fine. These transfers typically take 5 business days and you should refrain from transacting on the account when you are ready to transfer. Don’t have open limit orders, expiring options, recurring ACHs open otherwise RH will reject your request.
Edit: I am not a tax advisor so nothing I say should be construed as tax advice, so I cannot tell you what you should or should not do. Please consult a tax professional if you have specific questions.
Edit #2: Again, I am NOT offering advice to anyone. This post should not be interpreted as me telling you to transfer your account. That decision is fully YOURS to make.
Edit #3: I kind of touched on this, but an ACATS transfer will lock your account for the duration of the transfer, preventing you from trading. You need to be ok with not trading for ~5 business days (this can take longer depending on how long it takes the broker to review) so be cognizant of that given the market’s recent volatility.