This shows the total number of single family homes and condos/TICs sold during the first seven months of the year. It's easy to see we're back to and surpassed the volumes of 2006 and 2007, prior to the housing and economic meltdown.
This second graph, while very busy, also explains some of the seasonality of the San Francisco market.
(Click on the graph to see a larger version.) As in many real estate markets, San Francisco generally experiences two sales peaks each year. The most pronounced is the so-called spring market where sales peak in May or June. A second, less pronounced peak usually happens in October.
One important fact to keep in mind with these graphs and numbers -- "Sales" are recorded as of the day escrow closes. The decision to buy was generally made 30 days prior to close of escrow. So the peak in June represents sales where the decision to buy (go into contract) was made in May. The opposite is also true -- the dip in sales in September represents a lack of buying activity in August.
(These statistics are taken from the San Francisco Multiple Listing Service).