JPMorgan Chase & Co has today reported a much better than expected 42% jump in fourth-quarter profit.

The increase was driven by the release of some of the reserves the bank had built up against coronavirus-driven loan losses and continued strength in its trading and investment banking units. 

The bank's net income rose to $12.1 billion, or $3.79 per share, in the quarter ended December 31, from $8.5 billion, or $2.57 per share, a year earlier. 

Revenue rose 3% to $30.2 billion. 

During the quarter, JPMorgan released credit reserves of $2.9 billion, boosting its profit. 

Excluding the reserves, the bank reported net income of $9.9 billion, or $3.07 a share, which was well ahead of Wall Street estimates of $2.62 per share, according to Refinitiv. 

Investment banking revenue surged 37% to $2.5 billion, driven by higher advisory fees across all its products. 

"While positive vaccine and stimulus developments contributed to these reserve releases this quarter, our credit reserves of over $30 billion continue to reflect significant near-term economic uncertainty and will allow us to withstand an economic environment far worse than the current base forecasts by most economists," its chief executive Jamie Dimon said. 

The big US lenders spent 2020 grappling with the economic fallout of the Covid-19 pandemic, setting aside billions to cover expected loan losses.

Analysts are expecting a rebound in their profits in 2021, as a number of banks start releasing reserves. 

The pandemic also caused a plunge in short and long-term interest rates early in the year as the US Federal Reserve pumped money into the financial system to shore up the economy. 

That led to a record reduction in net interest margins - the difference between what banks charge for loans and what they pay out to depositors. 

But JPMorgan still ended the year in better shape than most of its peer lenders, thanks to continued strength in investment banking and trading, which benefited from volatility in financial markets as investors reassessed their portfolios at the end of the year.