On New Year's Day, NYSE Euronext (NYX.DL) announced its quarterly changes to the circuit-breaker triggers. These are safeguards against market panics that would put a temporary stop to NYSE trading if the Dow Jones Industrial Average (^DJI -1.17%) fell too far, too fast.
The trigger levels have generally stabilized over the last year, in concert with the Dow's overall direction:
Q1 2012 |
Q4 2012 |
Q1 2013 | |
---|---|---|---|
Level 1 Halt (generally a 1-hour trading pause) |
-1,200 points |
-1,350 points |
-1,300 points |
Level 2 Halt (generally a 2-hour trading pause) |
-2,400 points |
-2,700 points |
-2.650 points |
Level 3 Halt (no more trading that day) |
-3,600 points |
-4,050 points |
-3,950 points |
But this update came with a surprise: The NYSE will switch its trigger calculations trom the Dow to the broader S&P 500 (^GSPC -0.78%) index on Feb. 4.
The exchange did not say what brought on this sudden and previously unannounced change in philosophy. Both the Dow and S&P 500 indexes are managed under the S&P/Dow Jones Indices umbrella, which is a joint venture between Dow Jones owner CME Group (CME 0.35%) and S&P manager McGraw-Hill (SPGI -0.25%).