Hello,
I made beatthecouch.com in July and it’s basically a game where you try to beat the S&P 500 and buy/sell when you want. Your opponent is a couch. It buys on day one and never sells.
Now over 100K+ games later, the hypothesis stands: it’s not wise to try to trade and time the market. Here’s the original data from the actual games itself.
Source: the game’s own database, every completed game Jul 12 to Aug 28. Tool: Python and matplotlib. Market data: S&P 500 daily total returns 1928 to 2019.
thanks!

Years ago, I managed a high-end restaurant. And twice a year a local brokerage firm would rent out the entire restaurant (to the tune of about $30,000) and treat their best clients for dinner.
I always asked the brokers what they invested their own money in. The answer was always the same, an index fund.
Every actual expert who is not trying to sell you something will tell you the same