The [headline that caught my eye this week](https://www.msn.com/en-us/money/economy/the-stock-market-has-not-been-this-expensive-since-the-dot-com-bubble-s-peak-history-says-to-prepare-for-what-might-come-next/ar-AA2bJWt8?ocid=BingNewsVerp) says the market hasn't been this expensive since the dot-com bubble peaked. I've written about stretched valuations before, including the Shiller CAPE ratio warning back in August, so this isn't news to regular readers. But it's worth sitting with, because I was investing in 2000 and I remember exactly what that felt like.

The uncomfortable part is that expensive markets can stay expensive for years. The CAPE ratio was elevated in 1996, and the crash didn't arrive until 2000. Anyone who sold in 1996 missed four more years of gains. Valuation tells you about the next decade of returns; it tells you almost nothing about the next six months.

But valuation does tell you something important about risk. When you pay top-of-cycle prices, the downside scenarios get worse. If stocks are priced for perfection and perfection shows up, you earn modest returns. If anything goes wrong, there's a long way to fall.

So what does preparing actually look like? Not selling everything and hiding in cash. I tried market timing in my thirties and it cost me more than the 2008 crash did. Preparation is smaller and less dramatic. Check how much of your portfolio rides on a handful of AI-driven mega caps, because the S&P 500's concentration means many people own more of that bet than they realize. Make sure your bond allocation actually matches your age and your timeline. Rebalance, which mechanically means trimming what has run up, whether or not it feels comfortable.

Ask yourself a simple question. If the market dropped 30 percent next quarter, would you sell, or would you keep buying? If you don't know, that uncertainty is the thing to fix now, in a calm moment, not during the storm.

I'm not predicting a crash. I'm 62 and I've stopped predicting anything. I'm just saying the price of admission is high right now, and the people who got hurt worst in 2000 and 2008 were the ones who assumed the good times were structural. Own broadly, keep some dry powder, and let time do the heavy lifting.

As always, this is my perspective, not professional financial advice.