Just noticed something interesting in the latest SEC filings. Gagnon Securities completely bailed on Power Solutions International (PSIX) in Q4, dumping their entire 64,770 share position for about $6.36 million. The stock's been on an absolute tear though - up 140% over the past year, so this exit looks like textbook taking profits into strength rather than any fundamental concern.

Here's what makes this trade noteworthy. PSIX just posted record Q3 numbers: $203.8 million in sales (up 62%) and $27.6 million in net income (up 59%), with diluted EPS hitting $1.20. Through the first nine months of 2025, net income more than doubled year-over-year to $97.9 million. The company's riding a wave of data center demand, which management flagged as the primary growth driver. They're projecting a 45% sales increase for full year 2025.

But here's where it gets interesting. While the growth story is compelling, gross margins compressed to 23.9% as the company ramped production hard. That's the trade-off when you're scaling rapidly - you're managing operational risk alongside explosive growth. Gagnon's exit timing suggests they recognized this tension. When a stock doubles in a year, trimming or exiting isn't necessarily bearish. Sometimes it's just smart risk management.

Looking at where Gagnon reallocated capital is telling too. Their top holdings after the filing are now concentrated in positions like CDNA ($33.44M, 6.9% of AUM), WGS ($32.97M, 6.8%), AL ($31.92M, 6.6%), ENSG ($31.45M, 6.5%), and AMRC ($24.40M, 5.0%). The portfolio's consolidating into these larger positions rather than spreading across smaller industrial names that have already had massive runs.

Power Solutions International operates in a solid niche - they design and manufacture alternative-fueled and conventional engines, integrated power systems, and components for industrial, energy, and transportation markets. Their customer base spans OEMs in off-highway equipment, on-road vehicles, power generation, and specialty vehicles across North America and international markets. It's a legitimate business with real end-market demand.

As of mid-February 2026, shares were trading at $92.72 with a market cap of $2.14 billion, revenue (TTM) of $675.48 million, and net income (TTM) of $121.20 million. The valuation's gotten stretched after a 140% run while the broader S&P 500 only gained around 12% in the same period.

The real question for long-term investors: Does the growth sustain? If data center demand holds and margins stabilize as the company matures its production, PSIX could keep compounding. But after a parabolic move like this, protecting gains isn't irrational. You're watching a company executing well, but also one where operational leverage cuts both ways. When production ramps this aggressively, execution risk rises alongside the upside.

Fund managers like Gagnon aren't typically wrong when they take profits on 140% gainers. They're often just being disciplined about position sizing and risk. That said, the underlying business fundamentals still look solid - the question is whether the stock price already reflects the next few years of growth.