No. A bear market presents the best opportunities for buying valuable stocks and lowering your average cost, so why would you sell? It is also difficult to time the market and you never know if the market could bounce back up once you have sold. Simply average down and hold for the long term (5 years or more). 

Yes, Elon Musk is actually still early into his ventures at Tesla and SpaceX. Tesla's growth is accelerating even with plenty of global issues (supply chain, inflation, Ukraine-Russia war), so just imagine how much more the company will continue to grow after these few rougher years have passed. Many giga factories are also on the way and that will only increase production capacity for the dominant leader in the EV market. Let's also not forget his seemingly massive support from the online community, his influence on some cryptocurrencies, and his latest move into ownership of Twitter - plenty of potential there as well for him to tap on. Considering how his companies are doing and the influence he commands, he is well set-up to continue being the richest man on Earth in 2023.