After a calamitous early-morning sell-off, stock markets rebounded strongly Wednesday. A 500-point drop in the Dow Jones industrial average during the early minutes of trading was erased by 2:30 p.m., and at the close the index logged a gain of more than 200 points. The Standard & Poor’s 500 and the Nasdaq Composite indexes followed the same pattern.

In the end, it was yet another day of — here’s that word again — volatility. Fears of a widening trade war with China seem to have triggered the early declines. Recent days saw a pair of dueling announcements, with the Trump administration releasing its list of Chinese products getting steep new tariffs — including lots of electronic and industrial components — and China responding with plans to retaliate against US soybean farmers and automakers. The US tariffs would make imported Chinese goods more expensive, hurting manufacturers and consumers here. China’s levies would hurt US companies that send their products across the Pacific.

But this tit-for-tariff isn’t the only thing driving this market volatility. Investors may also be losing faith in the future.

The big financial promises of Trump’s presidency — a wish list that helped him build support on Wall Street — have either been fulfilled or abandoned. Tax cuts were passed, and a loosening of the Dodd-Frank rules governing financial institutions looks likely; meanwhile, momentum seems lost for any deeper financial deregulation or widespread infrastructure plan to boost productivity.

So when investors look ahead they see mostly risk and uncertainty. The trade war, to begin with. But also a Federal Reserve that’s committed to tamping down economic growth (and possible inflation) by raising rates, and government debts set to rise dramatically in the years ahead.

And this loss of hope for further policy changes may be sapping market momentum, especially when you consider that hope is a very real component of stock prices. Seriously. The value of a stock depends on people’s expectation of future profits, which reflects their sense for how individual companies — and the US economy as a whole — will perform in the future. More hope means higher expectations and rising share prices.

Instead, a touch of pessimism is shadowing the markets and making this week’s swings so different from the correction in January. Back then, it looked like stocks were falling for the best of all possible reasons, namely because workers were poised to get raises so big they would cut into corporate profits. Rising bond yields were evidence for this, suggesting a future of faster growth and rising inflation.

Not so this week, when bond yields have been moving up and down, in line with stocks. That paints a whole different picture, mostly devoid of hidden optimism.

Even with the late-day rally, the Dow and S&P 500 are down 8 percent from their January peaks. They have also erased all their gains for the year.

There are lots of ways out of this rut. Trump and his Chinese counterpart, Xi Jinping, could step back from the brink, opting for negotiation as a better way to resolve their disputes. Or the Fed could change course, holding rates low as a way to maintain economic stimulus.

Companies themselves could also ride to the rescue, with stronger-than-expected earnings reports. Those reports are coming soon, and signs of outsized profits would surely warm investors’ hearts.

Nor is that the only way for businesses to help. They could also accelerate their already-aggressive efforts to buy back their own company stock, using the windfall from Trump’s corporate tax cuts. Buybacks of that sort tend to boost prices by taking shares off the open market and limiting supply. This process is on hold for the moment, because regulatory rules prevent buybacks before earnings reports come out — but the window will open again in coming weeks.

For now, perhaps the most sanguine interpretation of this week’s market turmoil is that corrections always feel like this. By historical standards, market prices have looked inflated for several years. Now stocks are flailing about and hissing air, which is a lot better then the popping sound you get if you let bubbles grow too big.

And there is also this virtue. Big market swings can create real bargains. At the low points, stock prices drop far enough that they start to seem like a good value. And that excites investors who, like shoppers everywhere, love a deal.

In the latest round

of maneuvering:

The US government released a new list of more than

1,300

Chinese products it intends to slap with a 25 percent tariff. It includes farm equipment, televisions, light-emitting diodes, and machine parts.

China responded Wednesday

with a list of an additional

106

US products it says will face a 25 percent import tax. It includes soybeans, planes, and beef.

Evan Horowitz digs through data to find information that illuminates the policy issues facing the nation. He can be reached at evan.horowitz@globe.com. Follow him on Twitter @GlobeHorowitz.