Bitcoin you can buy small quantity instead of buying 20K at once because people expect some correction but it may or may not happen soon. So don't simply wait instead buy a small amount first and wait for again right time to enter. You can also consider adding some IOTA which actually corrected and slowly started moving up again. Good luck to you in crypto investments..
While many are expecting Bitcoin to make a big correction soon such a dip may or may not happen as the whole Bitcoin community is watching what can be the effects of the Bitcoin Futures to the overall market of Bitcoin. Will it be a catalyst for a surge or will it dampen the overall sentiment of the market considering that there are those predicting the futures to be an instrument in limiting the value of Bitcoin just like what is happening with gold and other fiat currencies. Yes, the best thing to do is really diversifying one's portfolio so as to spread the risks involved. Aside from Bitcoin, there are now emerging altcoins really worth investigating and investing with. Good luck to OP!