PBS高端访谈:此前异常平静的股市今起波澜

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John Yang: The past three trading days have been a roller-coaster ride for global markets. At this morning's opening bell on Wall Street, the Dow Jones industrial average plunged¹ more than 500 points, and then ended the trading day up more than 500 points, a 1,000-point swing. To help us understand this, we are joined by Neil Irwin, senior economics correspondent for The New York Times' Upshot. Neil, thanks for being here. This morning, you wrote that the key to keep in mind is to keep the long view in mind. So, having said that, what do we take from the last three days?

Neil Irwin: Well, I think the era of extreme low volatility² may be over, at least for a while. I think it might come back, but for now this period we had, all of 2017, not a single day of the stock market losing more than 2 percent. That's very unusual. And we have now had two of those days out of the last three trading sessions. This is clearly a more volatile³ environment. This is clearly a time when stocks are going crazy. That said, we're still only at about mid-December levels. We're down only a little bit for the year. We haven't even hit the correction level of losing 10 percent in stock value. So, this isn't a crisis. This isn't something to worry about too much. At the same time, it's certainly is a little teeth-chattering when you watch the daily stock market ticker.

John Yang: And, in a way, it was a return of volatility. We hadn't seen this sort of volatility in quite a while. Why do you think it came back this way?

Neil Irwin: There seems to be some self-fulfilling cycles happening. There are a lot of investors⁶ betting against volatility. There is also some news behind this. There was a jobs report Friday that suggested wage growth is a little stronger than it appeared. That suggests maybe there are inflationary pressures in economy. Maybe the Federal Reserve will have to raise interest rates a little faster than they have been. Now, I would add, those are basically good news for American workers. If you see bigger paychecks, that might be bad for corporate⁷ earnings⁸, but it's not bad if you're earning a paycheck. So there are some fundamentals and also a kind of reversal of these long-building effects that were depressing volatility in the market.

John Yang: Not only volatile, but sort of the velocity⁹ of the motion, the movement, the downward movement yesterday in particular, does that suggest that there was some program trading going — that was pushing that, driving that?

Neil Irwin: It does. You have institutions that have billions of dollars in assets that are making these huge decisions, huge trades based on what the computers want to do. No humans even touch them. That can create these vicious cycles, these self-reinforcing cycles. One clue that that might be part of what's going on, if you look at some of the other markets that have less of that type of activity, the bond market, the commodities markets, those haven't moved nearly as much. They haven't been nearly as volatile. This seems to be mainly confined to the stock market so far. That is a hint that something weird¹⁰ is going on, that this isn't just about fundamentals and about people reassessing their view of the economy.

John Yang: Much was made yesterday that the gains of 2018 had been wiped out, but if you, again, take the long view, as you counsel in your column this morning, talk about the larger trends that we're seeing in the stock market.

Neil Irwin: Yes, fundamentally, we have had a — this is a recovery that dates back to 2009. We haven't had a bout⁴ of instability like this since early 2016, so two years. You know, this has been an unusually calm time. You know, part of the tradeoff of stocks, they have longer — higher long-term returns than other assets, but the price is some volatility. So, this is kind of the price you pay for longer-term returns. And now we're kind of experiencing it all at one time, instead of in a more kind of gradual rate.

John Yang: And what we saw yesterday or the last three days really had nothing to this with sort of the fundamentals of the economy.

Neil Irwin: Well, the thing is, if you look at the economic data, there's no sign of problems. The weekly jobless claims, the employment report, anything you want to look at, industrial production, those numbers are all very solid. All the things you would look to as a leading indicator¹¹ that we might have a recession or even just a downturn, those aren't showing up in the data so far. Unless the stock market knows something that isn't showing up, things look pretty good in the economy right now.

John Yang: And the market had been sort of soaring at a high altitude. There had been a lot of talk and a lot of people saying that the stock market was overvalued compared to the price/earnings ratios that we were seeing. But this wasn't a correction.

Neil Irwin: Yes, technically¹², a correction is a 10 percent drop. Even after Monday's close, only down 8.5 percent by the S&P 500, and then of course rebounded¹³ today. So we're even closer to the high. This is not yet technically a correction. It still could get there. We might have a few more days of volatility. Who knows. But the reality is, in this — in the grand scheme of things, this is not the biggest correction. And, again, we're only back to mid-December levels. So, as long as you're a long-term investor⁵, you're doing fine. It's only if you plowed¹⁴ money in, in early, mid-January that you might have endured some losses.

John Yang: How do you explain what happened today, sort of that big — the market fell out of bed and then finished up 500…

Neil Irwin: It gets back to these technical factors and algorithmic trading. There's a lot of money sloshing around very rapidly, often without human hands touching¹⁵ it. And that creates these unpredictable swings. Will that be — will we go back to the old normal of low volatility? I don't know about that, but all signs are we might have some — another few sticky days before it's all over.

John Yang: A few more sticky days perhaps. Neil Irwin of The New York Times' Upshot, thanks for being with us.

Neil Irwin: Thank you, John.