Round integers like 1,700 on the S&P 500 are well and good, but savvy traders have their minds on another number: 2.75 percent
That was the high for the 10-year yield this year, and traders say yields are bound to go back to that level. The one overhanging question is how stocks will react when they see that number.
"If we start to push up to new highs on the 10-year yield so that's the 2.75 level—I think you'd probably see a bit of anxiety creep back into the marketplace," Bank of America Merrill Lynch's head of global technical strategy, MacNeil Curry, told "Futures Now" on Tuesday.
And Curry sees yields getting back to that level in the short term, and then some. "In the next couple of weeks to two months or so I think we've got a push coming up to the 2.85, 2.95 zone," he said.
Jim Iuorio, the managing director of TJM Institutional Services and a CNBC contributor, thinks the old highs for the 10-year yield are in the cards, but he says that's because of expectations about what Federal Reserve Chairman Ben Bernanke might be thinking.
"The chairman wants to control volatility by sending rates up to a higher level, but he wants to control the rate at which they go higher. The spike up to 2.75 that happened three weeks ago alarmed him," Iuorio said. "Now the market thinks he's ready to start opening the door a little further. So we're headed back to those old highs."
(Read more: Why I'm selling bonds ahead of the Fed)