> If you decide to invest $100,000 into the stock market because you agree with my reasoning in this post, then it would make a lot more sense to invest $10,000 a month over the next ten months than invest all of the $100,000 this month.

Depending on the equity, you are essentially sampling from a skewnorm & summing over 10 variates. eg. if you invest in the broad market, ^GSPC (your s&p 500) has a skew of +0.4 and a variance of 2.8, so your five number summary works out to

summary(mapply(function(x){sum(rsn(10, dp = cp2dp(c(0,1.67,0.4), "SN"))[1:10])},1:10000))

[-18.3, -3.7, -0.2,3.4,18.8]. While the median scenario is net neutral, you do end up underpaying 3-4 times if you fall below the first quartile.

otoh, if you are feeling frisky and want to dump 100k into robinhood over the next 10 months, $hood has a skew of -0.88 & a variance of 26.3, so 10k realizations of this scenario -

summary(res<-mapply(function(x){sum(rsn(10, dp = cp2dp(c(0,5.1,-0.88), "SN"))[1:10])},1:10000))

yields [-70.8, -10.6, 0.7,11.4,47.5] - much more interesting set of circumstances!

I guess he's betting on prices generally headed down over the next 10 months, so he significantly underpays if things go per plan.