If it's a bubble that big it's

1) the only reason any part of the economy is growing at all

2) the only reason US banks aren't bankrupt due to the commercial real estate debacle they got themselves into

In other words, if this is a bubble, if this pops, we're back in the 2008 situation. Where banks will go bankrupt one after the other like dominoes (in the sense that this amount is large enough that large banks will fail their financial obligations). And you can argue as much as you want based on "real" valuation metrics but none of your investments, not even cash dollars or even gold, will come out of that one intact.

Fortunately, there's the counterargument: you know what else is higher than ever? The revenue produced by the software industry. To the point that at the moment you can say, as crazy as it sounds: if revenue of the big software firms keeps growing the way it IS currently growing, this is not enough investment.

In case you're wondering what exactly that means, not enough investment. Think of it like this: you're selling shoes. If you invest too little in new shoes (or whatever resources you need to sell shoes), then you will have to tell customers coming in "sorry, all out of shoes, take your money elsewhere". Currently it's not enough investment. If this growth rate keeps up for 1.5 years, Amazon will have to close the store to anyone who wants more machines, in fact they are turning away large customers right now at Amazon, Google and Microsoft. That's where the "spend more now" madness is coming from. Is it unjustified?

Well, it appears not.

I think you’re wrong.

Time will tell.