Nuvei stock fell 45% after its second-quarter earnings. Are investors overreacting, or is it a sign of long-term weakness? Let’s find out. Last month, Canada’s payments processor Nuvei’s (TSX:NVEI) stock fell 45% after its second-quarter earnings. It reported weak earnings, a lower 2023 outlook, and a weaker medium-term revenue growth target. For a small tech company like Nuvei, which is operating in an already crowded payments platform market, a downward revision in its revenue target hints that growth is slowing. And with liquidity drying up in the economy because of high interest rates, investors are becoming more risk averse. Is…