The S&P 500, spurred by upbeat earnings reports, rose 4.4 percent last week.

That may be hard to repeat this week as data on existing home sales for March are expected to be released on Tuesday and show further declines. The Street is expecting March sales to drop to 4.95 million from 5.03 million in February.

“Unfortunately, we have to look for further declines,” Mike Moran, of Daiwa Securities America, told Thompson Financial. Moran said last month’s increase was likely an “aberration” and “will correct in March.”