The British Guiana 1c magenta sold for $7.90 million at Sotheby's on June 17. This comes to $9.48 million including the premium. It went to an anonymous phone bidder.

This is below the $10million-$20million estimate, but well above the world record for a stamp which was 2,875,000 Swiss francs (approximately US$2.2 million), set by the Swedish treskilling yellow in 1996.

The bidding began at $4.5milllion, possibly indicating this was the reserve. 

The Smithsonian has requested the stamp for an event in the autumn, and the NY2016 show also wants to show the stamp.

Linn's Stamp News in the US reports Sotheby's Vice Chairman David Redden as saying: 'I can only say that given who the buyer is, we will be seeing more of this stamp in the future.' Redden also indicated the buyer was a collector rather than an investor. 

A video of the sale, taken by the owner of StampsAreArt.com, is available at this link.