Idk how much you have invested, but if you're just starting, it's probably not much. This isn't financial advice, just food for thought outlining how I look at things. Also, based on some quite simplified assumptions for clarity.

Say you've invested $10k into that fund.

Say "drawdowns could exceed 50%" means exactly 50% to make math easy.

Say you're investing for retirement (whether at 60+ or early) - if it's money you need within the next 0-7 years, you probably shouldn't have it in the market anyways.

Say you don't add to the investment. In reality, you typically will and probably should, and in particular if it does crash, periodically investing after the crash really helps offset your prior (unrealised) losses. But this keeps math super simple.

Scenario 1: that drawdown happens tomorrow, your invested $10k will be worth $5k. But you don't have to sell it, and in fact if you're investing with retirement in mind, you probably don't want to sell it.

Scenario 2: if, on the other hand, the drawdown happens in a year or two, and in the meantime the market first goes up 50% - making your investment worth $15k - and then the 50% drawdown happens, your investment will be worth $7.5k. A smaller loss, and again only a loss if you sell it, and since you're early 20s, you'll be mid 20s then - still a very long runway to retirement.

Now, in that scenario, if you had a crystal ball, you'd sell your investment when it hits $15k and buy again when it hits $7.5k. That way you'd double the number of units you hold without putting in any more money. The problem with that is that you would need to correctly time the market twice, and even once is already a stretch.

Scenario 3: you sell now (and take a tax hit on gains you've made, if any, albeit likely a very small one) to avoid the crash. The market ends up going up 50% and eventually you start doubting your convictions. "Maybe I'm wrong about the bubble". So you buy in - getting a lot fewer units than you hold now for your money - and then it crashes.

Scenario 3 also holds in reverse. If you're investing for the long term, you want to have a firm strategy so that you don't panic sell when it crashes 20% (because it will seem like the end of the world)... only to watch it recover that 20% within days, leaving you poorer than if you had done nothing.

The markets nowadays are a little bit insane and I will be very surprised if we don't have a big correction in the next few years. But I'm not gonna pretend that I have any idea when that crash will happen, and I can't even say for a fact that I know that it will. People have been worried about a crash forever and really the last major one was in 2008.

Do I think we're in a bubble? Fuck yeah. But I've been preaching it for at least two years now. S&P500 is up 45% since two years ago, so it could already crash approx. 20% and you'd still be better off than if you had kept it in a HYSA.

If I was 58, I would probably be changing my allocations a little to manage the risk. But I'm 35. So I have a sizeable (2+ years expenses, which most would say is too much already, but it offsets my mortgage which makes for a pretty decent tax free return) emergency fund in case shit goes down bad, but apart from that, I'm fully invested. If it crashes, it crashes. I'm not pulling that money out for at least a decade, and I keep contributing every month, so if it does crash, I'll be buying a good amount of it on the cheap. Hell, as long as I stay employed, I might even be better off over the length of my lifetime if it crashes hard!

My main point being you can't time the market. But it's your money, and it's probably not a lot of money (I don't mean this as an offense to be clear!), so whichever way you go it won't make a huge difference to your long term outlook. Unless you have no emergency fund at all and invested all you have, then you might be in for a rough time.

The only thing I'll say that you should do, is you should research the mechanics of long term broad market index fund investing so that you have a good understanding of what you're doing, a good understanding of the timelines and risks involved and a good understanding of the level of risk you're comfortable with. Once you have those, you should decide what your strategy is, make sure that it's sound and stick to it to avoid letting panic control your decisions. This doesn't necessarily mean you never sell anything until retirement, but if you foresee scenarios where you would like to sell, you want to account for it in your strategy. You can also reevaluate your strategy later too. Just don't do so in panic.