"Recessions have tended to be good buying opportunities for Small Caps," they added. The bank also noted that the Russell 2000's forward price-to-earnings ratio has been trading in the 11-13 times range, "which tends to mark its bottom." Citi U.S. equity strategists earlier this week wrote "stocks down the market cap spectrum appear closer to pricing in recession than their Large Cap peers."

Graphic: Small caps vs US stock market,

Not everyone is convinced it is time to buy small caps. Appetite for shares of smaller companies could quickly sour if inflation remains persistent and the Fed is forced to raise rates more aggressively than expected, inflicting more pain on the economy. The central bank hiked interest rates by 2.25 percentage points already this year as it fights the worst inflation in four decades, but Powell offered little specific guidance about what to expect next during his news conference following Wednesday's Fed meeting. "There might be some more disappointing economic news to come even though the market is (already) pricing in somewhat of a mild recession," said Angelo Kourkafas, an investment strategist at Edward Jones, which recommends clients "underweight" small caps for now. The economy's strength faces a key test next week, when the monthly U.S. jobs report for July is released. Economic data is expected to be especially important for market sentiment in the next two months to give cues for the Fed's next moves.

Analysts at the Wells Fargo Investment Institute said smaller companies will be challenged to maintain profitability and healthy cash positions as the economy slows. The firm projects the U.S. economy will be in a recession in the second half of 2022 and into early 2023. "We don't think this move in small caps has legs," said Sameer Samana, senior global market strategist at the Wells institute.

(Reporting by Lewis Krauskopf and David Randall in New York; Editing by Matthew Lewis)

By Lewis Krauskopf and David Randall