Fed Chair Janet Yellen said that she expects that Hurricanes Harvey and Irma will impact the American economy, but that those effects are unlikely to damage economic growth long-term.
The Fed's projections pointed to a quarter basis point rate increase later this year, with the rate hike widely expected to come at the December meeting.
Any reduction in the Fed's balance sheet could make it harder for banks and investors to borrow certain Treasuries in the repurchase agreement market, making it more difficult and expensive to bet on or protect against rate increases.
The S&P 500 .SPX gained 1.59 points, or 0.06 percent, to 2,508.24, clocking its sixth record closing high in the last seven sessions.
At 9:39am ET (1339 GMT), the Dow Jones Industrial Average was up 33.52 points, or 0.15%, at 22 301.86, the S&P 500 was up 4.44 points, or 0.17%, at 2 504.67 and the Nasdaq Composite was up 18.27 points, or 0.28%, at 6 466.74.
NAR said existing home sales slumped by 1.7 percent to an annual rate of 5.35 million in August after tumbling by 1.3 percent to a rate of 5.44 million in July.
Oil service stocks moved sharply higher over the course of the trading day, driving the Philadelphia Oil Service Index up by 1.8%.
Advancing issues outnumbered decliners on the NYSE by 1,705 to 773. With the gain, the average reached a two-month closing high.
Nike, a Dow component, fell 1.68 percent after a slew of price target cuts by brokerages on concerns about intensifying competition from Adidas.
Among stocks, Tesla was down 1.17 percent in premarket trading after Jefferies started coverage of the electric auto maker's stock with "underperform".
The major European markets have also shown a lack of direction on the day. France's CAC 40 Index increased 0.3 percent, Germany's DAX Index added 0.3 percent, while the UK's FTSE 100 Index climbed 0.5 percent. "Should the Fed go ahead and announce a balance sheet normalisation the dollar will rally but the extent of the move hinges on any hints about the Fed raising rates in December".
Meanwhile, Caterpillar rose two percent, hitting a record high after UBS analysts said the company was due to benefit from growing spending in the mining and construction sectors.
Trading on Thursday may continue to be impacted by reaction to the Fed announcement, although traders are also likely to keep an eye on reports on weekly jobless claims and Philadelphia-area manufacturing activity.