The major indexes took a breather Tuesday, with the Dow Jones Industrial Average dipping 0.2% to 48,367.06, the S&P 500 sliding 0.1% to 6,896.24, and the Nasdaq falling 0.2% to 23,419.08. But beneath that quiet surface, a handful of stocks put on quite a show.

Here's what had retail traders buzzing throughout the day.

Nio Gets a Boost From Beijing

Nio Inc. (NIO) shares climbed 3.00% to close at $5.50, after touching an intraday high of $5.79. The stock trades in a 52-week range between $3.02 and $8.02.

The catalyst? China's National Development and Reform Commission confirmed that vehicle trade-in subsidies will keep flowing through 2026. That's good news for EV makers banking on government support to drive replacement demand. For Nio, which has been navigating a competitive and price-sensitive market, any signal of sustained policy backing helps stabilize the outlook.

Profusa's Wild Ride on Debt Restructuring

Profusa Inc. (PFSA) had the kind of day that makes penny stock traders' hearts race. Shares exploded 78.33% to $0.12, hitting an intraday high of $0.17 before settling. The 52-week range stretches from $0.065 to $2.40. Reality set in during after-hours trading, though, with the stock dropping 14.12% to $0.10.

The company announced a restructuring of its senior secured convertible notes, raising the conversion floor price from $0.10 to $0.35. Management positioned this as a move to reduce potential shareholder dilution and strengthen the balance sheet. They also eliminated mandatory cash and equity amortization payments that were scheduled to kick in during early 2026, which should ease near-term cash flow pressure.

The company framed these changes as de-risking moves that limit equity issuance at distressed prices while improving financial flexibility. But let's be clear: Profusa remains a high-risk micro-cap facing Nasdaq non-compliance and ongoing operational challenges. The pop was dramatic, but the fundamentals are still fragile.

Tim Cook Doubles Down on Nike

Nike Inc. (NKE) barely budged during regular trading, dipping just 0.03% to $61.19, with an intraday range of $60.64 to $61.30. The 52-week range runs from $52.28 to $82.44. The stock did tick up 1.5% to $62.13 in extended trading.

What caught attention wasn't the price action but the insider move. Apple Inc.'s CEO, Tim Cook, purchased $3 million worth of Nike shares last week, bringing his total stake to 105,480 shares valued at $6.04 million. When one of the world's most successful tech executives puts serious personal money into a struggling athletic wear giant, people notice. Whether it's a vote of confidence in Nike's turnaround or just portfolio diversification, it's a fascinating data point.

FTAI Aviation's Power Play

FTAI Aviation Ltd (FTAI) soared 14.30% to $197.54, with an intraday high of $199.88 and a low of $176.68. The 52-week range is $75.10 to $199.88.

The jump followed the company's announcement of FTAI Power, a new venture that will convert aircraft engines into power turbines designed to address AI-driven power shortages. Production is expected to begin in 2026. It's a clever pivot that connects two major trends: the glut of retired aircraft engines and the insatiable appetite for power in AI data centers. If executed well, it could open a significant new revenue stream.

Under Armour's Insider Vote of Confidence

Under Armour Inc. (UAA) rose 7.64% to $5.14, trading between $4.91 and $5.20. The 52-week range is $4.13 to $8.72. The company's Class C (UA) stock jumped 8.59% to $4.93.

The rally was fueled by a large insider purchase from Fairfax Financial Holdings, which scooped up 15.68 million shares, significantly boosting its stake in both Class A and Class C shares. That's the kind of move that signals real conviction.

Under Armour also reported second-quarter adjusted EPS of 4 cents, beating expectations, with gross margin coming in at 47.3%. That's down year over year but still ahead of consensus. The company guided fiscal 2026 revenue down 4% to 5% and adjusted EPS to 3 to 5 cents, citing soft demand and tariff pressures.

On top of that, Under Armour expanded its fiscal 2025 restructuring plan, adding $95 million in charges related to separating the Curry Brand. The company also lifted its fiscal 2026 adjusted operating income outlook to $95 million to $110 million. Fairfax's increased stake signals confidence that the restructuring and turnaround strategy will deliver longer-term gains, even if the near-term picture remains choppy.