American equities are pricing in some pretty wild numbers right now. We're looking at a Shiller P/E ratio sitting around 45x—basically the highest valuation mark we've seen since the dot-com peak back in 2000. That's not chump change. The US market is essentially trading at levels that historically signal one thing: things have gotten expensive. Real expensive. When you stack this against where we've been before, the comparison is hard to ignore.