Shares of Kirby Corporation (KEX) plunged 7.42% in pre-market trading on Thursday, despite the company reporting better-than-expected second-quarter results. The sharp decline comes as investors focus on the marine transportation and diesel engine services provider's cautious outlook and concerns about potential trade policy impacts.

Kirby reported second-quarter earnings of $1.67 per share, up 17% year-over-year and slightly above the analyst consensus of $1.65. Revenues rose 3.8% to $855.5 million, also beating estimates of $851.4 million. However, the company's forward-looking statements have raised concerns among investors.

CEO David Grzebinski warned that recent shifts in trade policy have introduced new complexities to near-term planning, potentially impacting trade flows and demand, including in the chemicals sector. Kirby now expects to be closer to the lower end of its prior full-year EPS growth guidance of 15-25% if current softness persists. This cautious outlook, coupled with mentions of softening barge utilization and potential pressure on spot market pricing in the inland marine segment, appears to be driving the stock's pre-market decline. The market's reaction suggests that investors are prioritizing future uncertainties over the company's solid Q2 performance.