The Covid-19 pandemic has been very good to Wall Street. Central banks and governments have shored up companies and markets, bolstering securities firms’ trading revenues to unprecedented levels. Nowhere has the bonanza been more consequential perhaps than at Britain’s Barclays Plc, vindicating Chief Executive Officer Jes Staley’s strategy of sticking with investment banking and buying him time in the job. The boon may not last, however.

Barclays on Friday said income from trading rose 29% to 1.6 billion pounds ($2.2 billion) in the third quarter — a surge that beat the average of Wall Street peers. The U.K. firm posted its best third quarter in buying and selling securities. Overall, it posted pretax profit of 1.1 billion pounds, ahead of analyst estimates. Provisions in the three months through September 2020 were lower than expected.

By some measures, Barclays is emerging from this stage of the pandemic stronger than when it went in. The bank has its highest ever capital and liquidity positions after creating a pot of 9.6 billion pounds of reserves for potential credit losses from the Covid-19 recession. Barclays has one of the healthiest balance sheets in its “modern history,” Staley said.

The sharp increase in securities revenue has helped the bank weather the hit from the economic contraction in the U.K. and the U.S. — markets where it has sizeable unsecured credit businesses. A less diversified Barclays may not have remained profitable.

And the bank is chipping away at the business of its investment banking rivals. Barclays estimates that it increased its share of trading activity among the biggest firms to about 5.1% in the first half, up from 3.6% in 2017. While some of its large U.S. peers are also growing (more slowly), its European rivals have been retreating from this business.

Hanging on to that market share will help once trading activity normalizes. But this boom in buying and selling stocks and bonds won’t last forever. Staley has had an element of good fortune in how the pandemic has benefited his investment bank, an area in which he’s keen to keep investing. But will things still look the same way once trading returns to its pre-Covid levels?

Shareholder activist Edward Bramson has called on Barclays to shrink its trading activities and focus on extracting more revenue from its corporate customers. In fairness, Staley is keen to invest in corporate banking, too, recognizing the bank’s weaknesses.

Asked about the longer-term outlook for trading, JPMorgan Chase & Co.’s Jamie Dimon said recently that the total pool of assets has grown, pointing to higher revenue for those who buy and sell them. He added that future revenues may as a result be better than previous years, but we “just don’t know.” Another senior banker told me 2021 may be only marginally better than 2019. Last year, returns at the Barclays investment bank were a drag on the group.

Staley said on Friday that it would be nice to be the CEO in “kinder winds,” after tackling the impact of the coronavirus and the firm’s restructuring. The trouble with trading is that sometimes it blows in the wrong direction.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

Elisa Martinuzzi is a Bloomberg Opinion columnist covering finance. She is a former managing editor for European finance at Bloomberg News.

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