Well gold is the way to go if you want to diversify your investing. Both bitcoin and gold are very solid investments, although people tend to forget that.
Especially when it comes down to bitcoin, it's underestimated

Both are indeed solid, but, you must consider the returns of the investments. You wouldn't want to end up investing $400.000 into the market and after 1 year, you get 3% profit with gold and 10.000% with crypto.