It's been one hell of a six-week stretch for condo sales in S.F., and we got together with The Mark Co president Alan Mark this morning to tell us why.

Alan says things really began picking up in mid-December, when extremely qualified—yet busy—potential buyers finally had time off work to make decisions. In addition, parents visiting during the holidays want to help kids buy a place so they go and take a look. The value of new construction condos in S.F. was $1,176/SF in January, 13% higher than a year ago, according to his firm's condo pricing index. Alan also is going to be on TV, confirming he's been participating in the local installment of Bravo's Million Dollar Listing. Alan says there were some "blockbuster" sales in January that will be reflected in the next set of numbers, and that there's little inventory for less than $1M.

This past weekend, interested buyers from Hong Kong flooded the market. At 8 Octavia (pictured), all three penthouses sold (Alan's team traded them for north of $2.5M). And 870 Harrison sold out and one is left at Amero. He says there are about 750 units available in S.F. that are new, many of which are at Tishman's Lumina, which just landed some juicy tenants. He marketed and sold the first two buildings at The S.F. Shipyard, with all 79 market-rate townhomes and flats under contract to close soon. Lennar is completing construction on Blocks 50 and 51, and those will close over the next couple of months.