Sotheby’s, the international auction house bought in 2019 by telecommunications magnate Patrick Drahi, reported Monday that it has sold $2.5 billion of art and collectibles so far this year.

The figures include more than $285 million from online-only auctions and $575 million in private sales. “The art and luxury markets have proven to be incredibly resilient, and demand for quality across categories is unabated,” Charles F. Stewart, Sotheby’s chief executive, said in the statement, acknowledging the challenge of selling high-end inventory during the coronavirus pandemic.

According to data independently compiled by Pi-eX, a London-based art market analytics company, Sotheby’s sales from relatively low-value online-only auctions from January through July were up 540% this year, but live auctions of $1.6 billion were down 42%, resulting in an overall fall of 25% in auction sales. Christie’s equivalent online and live sales declined by 53%, according to Pi-eX.

“Auction houses release detailed sales information to remind, at times like this, buyers and consignors that the art market is open for business,” said Doug Woodham, a former Christie’s president of the Americas who is now a managing partner of the New York-based company Art Fiduciary Advisors.

The art market, like so much of the global economy, has been profoundly affected by the COVID-19 crisis. Numerous art fairs and auctions have been either canceled or converted to an online-only format. So far this year, Sotheby’s has held more than 180 online auctions, including the single-lot sale in May of a pair of Michael Jordan’s game-worn Nike sneakers, which sold for $560,000, more than three times the presale estimate.