Stocks ended Wednesday's session slightly higher following a key inflation report that showed the fastest gain to consumer prices since 1982, but was mostly in-line from expectations. The S&P 500 posted the biggest gains, rising by 0.28%, while the Dow Jones Industrial Average and Nasdaq increased by 0.11% and 0.23%, respectively.

Here's how the market settled Wednesday:

S&P 500 Index (SPY  ): +0.28% or +13.28 points to 4,726.35

Dow Jones Industrial Average (DIA  ): +0.11% or +38.30 points to 36,290.32

Nasdaq Composite Index (QQQ  ): +0.23% or +34.94 points to 15,188.39

Robinhood to allow most employees to permanently work-from-home:

Popular retail stock trading app Robinhood (HOOD  ) said Wednesday it will let more of its 3,400 employees to permanently work-from-home moving forward. The plans were announced to the company's employees back in December.

"Our teams have done amazing work and built a strong workplace community during these uncertain and challenging times, and were expected to continue to offer them the flexibility they've asked for by staying primarily remote," Robinhood said in a blog post.

Robinhood added that it is building out its technological capabilities to support this new strategy and is creating programs to address all the possible challenges that remote working poses.

Consumer prices rise at fastest rate in nearly 40 years in December:

The U.S. Consumer Price Index (CPI) rose at its fastest rate in nearly 40 years in December, according to the Bureau of Labor Statistics report published Wednesday, demonstrating strong inflationary pressures on the recovering U.S. economy.

Prices rose by 7.0% year-over-year in December, marking the fastest annual increase for the index since June 1982. On a month-over-month basis, the rise was 0.5%, a slowdown from November's 0.8% gain.

Under the headline index, prices for used cars and trucks were the largest contributor to the overall CPI increase. The used cars index accelerated at a 3.5% month-on-month rise in December, marking a third straight monthly increase.

Core CPI, which excludes volatile food and energy prices, rose by 5.5% in December year-over-year, the fastest increase since 1991. That print was an acceleration from a 4.9% annual gain posted in November.

Here's how market benchmarks started trading soon after opening bell:

S&P 500 Index: +0.53% or +25.02 points to 4,738.09

Dow Jones Industrial Average: +0.47% or +170.06 points to 36,422.08

Nasdaq Composite Index: +0.83% or +130.07 points to 15,283.58