Bank of America Merrill Lynch chief investment strategist Michael Hartnett said it should be time to buy the when it nears 2,500 and the 10-year Treasury when the yield reaches 3 percent.
"My gut here is 2,500 and 3 percent on the 10-year. They are big, big levels. You expect the market to find a reason to buy at that particular moment," he said.
Hartnett, who has been calling for a correction, said the market should find a floor quickly but that it will have to retest that floor. A spot many strategists have been watching on the S&P 500 is the 200-day moving average, seen as the next technical zone to be tested. That is 2,538 on the S&P. The index dropped through it Friday afternoon.
Hartnett said there is a series of events that need to occur before the market sell-off is over.
"Maybe we need to see the dollar move up and that's the thing that causes investors to do things they least like to do: sell winners — tech, high yield, emerging markets. In these corrections, you sell hubris and buy humiliation. One measure of humiliation is everything goes through the wringer. Nothing is left unscathed," he said.
Merrill's proprietary bull and bear indicator, which has accurately called corrections, was flashing a sell signal Friday for a second week in a row.