The Harry Potter publisher Bloomsbury has issued its second profit upgrade of the year, lauding a lockdown reading boom, but the trend may not endure as coronavirus pandemic restrictions are lifted through the summer. The publisher, which last issued a profit upgrade in January, said February had also proved “exceptional” as readers looked for entertainment during the UK’s third stay-at-home order. Sales were driven by recently published titles including A Court of Silver Flames, the latest instalment of a series about female warlords by the fantasy writer Sarah J Maas, and Anna North’s Outlawed, which features a midwife’s daughter on the run in 19th-century America. In terms of its backlist, the perennially popular and evergreen Harry Potter books continue to achieve strong sales, as does the Dishoom cookbook. Bloomsbury expects full-year revenue to beat revised expectations of £171m and adjusted pre-tax profit to be “significantly ahead” of its already upgraded forecast of £14.8m for the year to the end of February. “The popularity of reading during lockdown is a ray of sunshine in an otherwise very dark last year,” said Nigel Newton, the chief executive of Bloomsbury. “February, the final month of our financial year, saw an exceptional sales performance for Bloomsbury as the surge in reading continued.” Bloomsbury said it was not yet clear whether the reading boom would continue. As a result, the publisher is keeping sales forecasts over the medium and long-term unchanged. “We do not yet know how consumer behaviour will change as academic institutions, shops and leisure activities reopen and whether this popularity will continue as restrictions are lifted,” Newton said. In October, the company reported its most profitable first-half year in more than a decade. Bloomsbury said it had repaid the £63,000 it initially took as part of the government furlough scheme, along with the temporary pay reductions staff took in the first three months of its financial year.