What investors can control amid changing conditions

Joel Dickson: So, when I think about indicators and portfolio pieces, it's what happens that changes the expectations that are currently priced in? Is there some sort of economic surprise that either reinforces the current high valuations that are in U.S. equity markets or that actually makes those valuations come into question?

At the end of the day, though, that's not really within an individual investor's control. And so, when we talk about the investing principles at Vanguard, talk about focusing on those things that are within your control and your success as an investor. Meeting your long-term goals are largely within your control.

How much you save and spend, how you diversify your portfolio to hedge against those things that you don't have control over, how much risk you take, how much cost you bear in making those investments. And so, a lot of times it's like, let's get back to those basics when talking about how does this happen. Because a lot of short-term expectations, or what you think might happen, is often just a bet that may or may not pay off.