A surge in revenues for investment banks last year does not make up for a "lost decade" of growth, and firms still need to pare back costs to stave off long-term threats to the industry, according to a sweeping new report.

Investment banks' stellar year, when trading revenues rebounded thanks to Covid-19 induced volatility and advisory fees surged, is unlikely to mean a longer-term revival, according to a report from management consultants Accenture into the future of the sector.