Stocks have rebounded from a rough April, led by some of the most unloved sectors over the past year that typically outperform when the economy is in a downturn.

This was again the case on Wednesday, with Utilities (XLU) rising about 0.9% compared to the S&P 500's (^GSPC) near-flat return.

Since April 16, around when the S&P 500 hit its recent bottom, Utilities have led the charge, rising nearly 12%, accounting for all of the sector's gains year-to-date. Consumer Staples (XLP) has risen almost 5% in that same period.

While these stocks are often tabbed with the phrase "defensive," referencing their outperformance amid sub-par economic performance, Wall Street equity strategists told Yahoo Finance a catch-up trade is the most likely reason for the surge, not recent weaker-than-expected economic data.

Considering both sectors had been among the worst performers in the S&P 500 over the last year, Truist co-CIO Keith Lerner reasoned there's an aspect of the move that is merely investors rotating into an area that has yet to participate much in the recent market rally.

Utilities entered March trading at its largest discount to the S&P 500 from a valuation standpoint (using a forward price-to-earnings ratio) since 2009, per Lerner. Meanwhile, Consumer Staples had underperformed the S&P 500 by almost 30% over the last year. This presented a potential buying opportunity in both traditionally "defensive" sectors.

"With markets up so much as we're up since October, people get nervous," Lerner told Yahoo Finance. "They want to rotate into something a little more defensive, take some profit taking...It's also just saying, 'Hey, what hasn't worked and what could have an opportunity to do some catching up or hold up better should the market correct?'"

Charles Schwab senior investment strategist Kevin Gordon conquered.

"Things had gotten so pessimistic for [Utilities] and you know, in turn, and relatedly, kind of making it more attractively valued for anyone who's looking for deeper value," Gordon told Yahoo Finance.