The 10-city and 20-city composite home price indexes rose 13.6 percent year-over-year, the report said. On a monthly basis, both indexes rose 1 percent on a seasonally adjusted basis, S&P said.
Economists had expected a year-over-year gain of 13 percent.
"Both composites' annual returns have been in double-digit territory since March 2013," noted chairman of the Index Committee at S&P David Blitzer.
"However, monthly numbers show we are living on borrowed time and the boom is fading," be said.
Noteworthy streaks in the month include a 17-month streak in which both the 10-city and the 20-city composites have increased on an annual basis. October was also the 25th consecutive month in which Phoenix posted an increase.
One streak ended. After 19 consecutive months of gains, home prices in San Francisco slipped slightly month-to-month in October, down 0.2 percent from September.
Thirteen cities out of 20 posted double digit annual returns in October with Las Vegas setting the pace at 27.1 percent, followed by San Francisco at 24.6 percent and Los Angeles at 22.1 percent.
Double-digit increases were also posted by San Diego, Calif. (19.7 percent), Atlanta (19 percent), Phoenix (18.1 percent), Detroit (17.3 percent), Miami (15.8 percent), Tampa, Fla., (15.2 percent), Seattle (13.1 percent), Portland, Ore, (12.7 percent), Minneapolis (11.3 percent) and Chicago (10.9 percent).