Wow, there are a lot of people making some very extreme and/or horribly informed commentary here.<p>There is no way to predict the future. In general, simply keep certain principles in mind.<p>1. Avoid "terminal conditions" - i.e., you lose all your money on an asset that goes bust and you have no money left to continue investing. I.e., Being 100% in Bitcoin or in your company's RSUs or options.<p>2. Minimize downside risk - Related to the first, avoid situations where you may incur large losses from having certain asset classes suddenly lose most of their value (e.g., having most of your money in the NASDAQ in 1999).<p>3. Keep some upside risk, however. Own some TLSA and Bitcoin (among others), but not too much. A small slice of your overall portfolio.<p>4. Have a balanced, diversified porfolio, even when it feels wrong, purchase under-performing asset classes. Typically, while reasonable people can have reasonable differences in opinion over precise allocations, one should have some commodities (Gold, silver), US equities (mix of growth and value, small and large cap), International equities (to include developing countries), as well as a mix of US and international government and corporate bonds, as well as a slice of cash. Real estate equity (home equity and or REITs should also be a part).<p>For that last part, especially, I frequently shill for the Schwab intelligent portfolio. You just put in your cash, and it will - in a very transparent way - allocate it to the proper asset classes and keep it balanced.<p>Of course, all the above assumes you have wealth already you are trying to preserve and grow. If one is just getting started, the advice above isn't reasonable, but that wasn't the topic brought up by OP.<p>TLDR, preparing for market crash means at all times - good and bad - keeping all my assets in proper proportion to one another, with an element of cash to be able to purchase more if any drops significantly.