Cash is the fuel that fuels the stock market rally and now investor cash is very low. By the way...when seeming "everyone" is low on cash in their accounts, what should you be doing? Raising your cash levels drastically and doing the opposite of what the masses do. Over time, the masses almost always get it wrong. https://www.zerohedge.com/news/2018-01-26/investor-cash-just-hit-all-time-low
Trading seems fun, exciting, exhilarating, etc. so it has a lot of draw to it. And many people won't dig deeper than the euphoric emotion that they feel. However, trading is MUCH harder than investing. And much of the industry is bent towards getting you to trade rather than invest.