Following a steep market decline on Thursday, all three major indexes spluttered through the trading session on Friday, leading to one of the worst weeks since 2011. (Tweet this)
Less than an hour before the closing bell, the Dow briefly entered correction territory on an intraday basis when it neared 6,516.22. To be in correction from its closing high of 18,312.39, the Dow has to hit 16,481.15. The Nasdaq also came very close to correction territory.
This week marked the worst for the since the week of Sept. 23, 2011 when it lost 6.54 percent. The Dow Jones industrial average is also having its worst week since then, when it had dipped 6.4 percent. The Nasdaq is having its worst week since August of 2011.
The Dow has fallen more than 500 points three times in the past five years. The last time was on Aug. 10, 2011 when the Dow dropped 519.83 points.
The Dow ended Friday's session down 528.47 points at 16,462.22. The S&P ended at 1,971.29, down 64.44 points. The Nasdaq closed down 171.45 points at 4,706.04.
Stocks extended their plunge on Friday as concerns about slowing global growth continued to weigh on investors.
Here are some other milestones hit this week:
—CNBC's Gina Francolla, Christopher Hayes and Evelyn Cheng contributed to this report.