The bell rang when it was over 10000. After the last trades processed, after the bell, it fell below. I was watching it.
I have live feed at Scottrade, & right after the market closed, they showed 9959. I checked just now, & they show an official close 9955.50. Yahoo Finance shows the exact same official close. I dont know if it hit 10,000 intraday, which is what you are saying. But what I stated was the offical closing figure, which is 9955.50
Symbol Last Change
Dow 9,955.50 369.88 (3.58%)
Nasdaq 1,862.96 84.43 (4.34%)
S&P 500 1,056.89 42.34 (3.85%)
10-Yr Bond 3.4260% 0.2180
NYSE Volume 8,067,414,500
Nasdaq Volume 3,537,768,000