A few couple of warm days, the appearance of a few tulips, and wham, homebuyer sentiment goes through the roof.  At least the results from the March National Housing Survey (NHS) seem to support that theory.  Net positive responses to whether it is currently a good time to buy and/or sell a home shot up 7 and 13 percentage points respectively in March, driving Fannie Mae’s Home Purchase Sentiment Index (HPSI) up by 5.5 points.