Median home prices and home inventory levels are up slightly in 24 of the 26 metropolitan real estate markets tracked by Altos Research, according to the research firm's latest Housing Market Update. In April, home prices edged up 1.82%, with San Francisco posting the largest home price gain of 4.87%, according to Altos 10-city composite index, which is based on a compilation of home price data. By way of comparison, home sale inventory was up 2.97% in March and up 6.83% in March, according to the index. Meanwhile, the national median home price hit $440,194 in April, compared to $432,307 in March. The uptick is in-line with seasonal expectations, which traditionally predict stronger home buying activity during the onset of the warm weather season. The largest home price drop occurred in Las Vegas, where prices fell 1.05%. Las Vegas and New York were the only two markets surveyed by Altos Research that experienced home price declines. In terms of home inventory, total inventory grew 11.45% in April, with the metro areas of Austin, Boston, Philadelphia, San Francisco, and Washington D.C. reporting double-digit inventory increases.. The only markets experiencing a drop in inventory included Phoenix (a 7.4% drop), Miami (a 5.5% drop) and Salt Lake City (0.02% drop). Altos says because the research firm watches the housing market in real-time, it contradicts more recent reports of dire home price drops. In the most recent Standard & Poor's/Case-Shiller index, the firm reported the average price of a single-family home fell 3.3% in February. Altos says once S&P begins reporting on the spring selling season, some of the more recent price increases will be incorporated in the findings. Write to: Kerri Panchuk.