THE MARKET is not that simple - so as any agent who tells you that prices in nassau are "going up" is either A. Lying to you or B. Doesn't understand the market.
When prices DROP enough and inventory shrinks a little - MORE SALES occur, which helps to stabilize prices...but that only lasts for a very brief time.
There are over 34,000 listings throughout Long Island and the entire market is moving about 1500 units a month...do the math - there's NO WAY the prices are "going up".
They're not. And they won't be for some time.
Now if you're looking to invest or just buy something - AND YOU'RE SERIOUS - I suggest you absolutely not use trulia or any other online resource solely to price the market.
Also - the prices of homes is one thing - THE INTEREST RATE is a comletely other issue.
If you are referring to recent unit sales volume, Trulia's data may not be reflecting all the recent sales because their stated source is assessor, title deed data and Trulia search traffic. These sources are generally delayed in reporting closed sales, therefore the current quarter number probably does not have all the closed sales for Syosset. Additionally, they are not including updated MLS data that is only available to member Realtor subscribers.