Stock Market Today, April 28: BigBear.ai Rises on Heavy Volume Ahead of Earnings as AI Defense Stocks See Increased Trading Activity

BigBear.ai (BBAI +10.99%), an AI-focused company serving defense and digital identity sectors, closed Tuesday at $4.12, up 10.46%. The stock advanced as investors responded to increased trading activity and anticipated the upcoming fiscal first-quarter earnings report, with attention shifting toward demand trends in defense-related artificial intelligence.

The company’s trading volume reached 64.9 million shares, which is about 54% above compared with its three-month average of 41.9 million shares. BigBear.ai went public in 2021 and has fallen 58% since its IPO.

How the markets moved today

S&P 500 (^GSPC 0.49%) slipped 0.48% to 7,138.8, while the Nasdaq Composite (^IXIC 0.90%) fell 0.90% to 24,663.80 as broader tech names faced pressure. Among information technology services peers, Leidos (LDOS +1.32%) closed at $146.15 (+1.32%) and Science Applications International (SAIC +1.16%) finished at $94.88 (+1.16%), both posting steadier gains than BigBear.ai’s move.

What this means for investors

BigBear.ai shares rose alongside increased trading activity in AI-focused defense and government analytics names, with the move occurring on elevated volume ahead of the company’s upcoming fiscal first-quarter earnings report. The stock’s gains also reflect renewed interest in smaller-cap companies tied to federal AI and data programs, rather than a single company-specific catalyst.

BigBear.ai’s business remains tied to contract-based work in areas such as defense intelligence, logistics, and decision-support systems, where revenue depends on securing government programs and turning its backlog into sales. Future contract announcements, backlog conversion, and updates tied to federal spending cycles will be the key market-moving signals for whether recent gains translate into sustained financial performance.