Been watching the tech rally and there's something that's been on my mind about one particular fund that's been absolutely crushing it lately. The Vanguard Information Technology ETF - that's what VGT stands for if you're wondering - has just been on another level these past few years. We're talking 120% gains over three years while the broader market was up roughly 73%. That's the kind of performance that gets people excited, no question.

But here's where it gets interesting. This fund has 320 stocks in it, which sounds diversified on paper. The problem? Three companies - Nvidia, Apple, and Microsoft - basically own nearly half the whole thing. Each one of these is sitting at over 12% of the portfolio, and they're carrying most of the weight. Everything else is basically noise in comparison, less than 2% each. So when you're really buying VGT, you're kind of betting on how those three mega-cap tech giants perform.

And these aren't cheap plays either. All three are trading at P/E multiples above 30, with market caps exceeding $3 trillion each. The valuations are stretched, which means expectations are sky-high. One thing I've noticed is that people tend to forget - when you have that kind of concentration in a fund, you're taking on more risk than the diversification number suggests.

Now, will there be a crash? Nobody knows. AI investment is still driving a lot of optimism, and companies are still pouring money into it. But I've seen how fast things can shift. Remember when those tariff headlines hit last year? Markets went into freefall pretty quick. That's the reality of holding something this tech-heavy.

So the real question comes down to you. If you're young and can stomach volatility, sure, VGT might still work in your portfolio. But if you're thinking about retirement or already there, this might be a good moment to ask yourself whether you want this much concentration risk. The fund's performance has been incredible, but past performance doesn't guarantee anything going forward. Risk tolerance really is the deciding factor here.