Sure. It's a really bad idea to try to time the market on a day to day basis. There's two sides to every trade, so you're generally playing poker against professionals with armies of quants.

But this game really just proves that you can't time the market while knowing nothing about the outside world.

Headlines sometimes matter.

Not all the time. Talking heads generally overstate how much one random speech matters, "politician X says Y, therefore stocks are reacting" is generally just over-analyzing noise. It's annoying to see post hoc rationalizations the norm in financial... in all news. People claim causation for anything they happened to read.

But occasionally, once a decade, say? Headlines do send a strong signal. "Crisis on Wall Street as Lehman Totters" was a headline that came just before the biggest cliff in 2008.

In February 2020 we didn't know as much as we do now, but people already started talking about difficulties in containment. China--which likes itself some economic growth (if only to keep the Party going)--decided a near total economic shutdown was necessary. The virus was already in a few dozen countries and Singapore was surrounded by container ships that couldn't dock.

So let's split out two separate claims:

1) The weak efficient markets hypothesis: you can't time the market blind.

2) Strong EMH: you can't time the market, not even once in a while, with your eyes wide open.

In defense of (2), the housing crisis really started in October 2007, and ended in February 2009. You can delve for headlines for those moments, but they are way more specious. Here's the real test: what will be the best signal of the rally after the pandemic?

1) China hitting zero active cases, reassuring the world it can be done.

2) Global new case "growth rate" below 1 for two straight weeks? [Growth rate being the ratio of today's new cases to yesterday's new cases, with lower than 1 a tipping point away from exponential growth, and probably the halfway point in the crisis.]

3) China keeping no new local cases even after reopening its economy?

4) Some decision about how to keep airlines solvent?

5) Unemployment nearing historical normals after skyrocketing beyond anything we've ever seen?

Any of these seem plausible. But who knows which will be right? However, if we are attacking strong EMH, we don't really have to time things maximally, we just have to do slightly better than the index. So maybe just wait until the S&P 500 has recovered a quarter of its losses and get in then?

Maybe the general problem with active investing is the financial sector's approach: hire people to study market signals full time and generate algorithms that can trade more and more actively. Full time people are expensive, and tuning algorithms is expensive. So that means you burn through fees (on top of probably not outperforming the market, because you're competing against noise).

If you hire people to do something full time, they will find ways to justify their time. If you hire someone to play rock paper scissors full time, and give them some of the highest bonuses in the world, they will come up with some very nice models. And usually not outperform a random thrower, but give you lots of reports on why and how they'll do better next time.

But if all the daily signals are noise except for one really blaring foghorn once a decade, maybe the better solution would be to hire a part time market hobbyist on a contingency fee. "Hey, if you see a signal that the entire market should be shorted, maybe short the market. You get two trades per decade max. Otherwise, just index and hold."

Probably also wouldn't work, but I really like the idea of some plumber in Poughkeepsie controlling billions of dollars in hedge fund money, you know, just as a side hustle.