The New York Stock Exchange suspended trading on the floor for the rest of the session Wednesday in Amazon, Booking Holdings and Alphabet due to a "price scale code issue," according to the exchange's website. The stocks traded normally elsewhere, including on their home exchanges.

The exchange said "any open orders in these securities will be cancelled" on its status page.

The issue affected stocks with prices above $1,000 which trade primarily at the Nasdaq. Booking Holdings (formerly Priceline), Amazon and Alphabet are the three highest-priced stocks in the S&P 500 and the only ones with prices that are four digits.

Overall trading volume was in line for the names as activity was normal on their home exchanges and other venues. Trading continued on NYSE's own Arca and NYSE-American systems in the stocks.

The NYSE floor began to allow trading in all listed securities (including those listed on Nasdaq) on April 9 of this year. Trading in all listed securities had already been occurring on the NYSE's electronic platform, known as NYSE-Arca, and on the old American Stock Exchange, now known as NYSE-American.