Schneider Electric has agreed to acquire PTC, an industrial software maker, for $205 per share in cash. The announcement sent PTC stock up 37.6% over the past five sessions, a gain that significantly outpaced the S&P 500's 1.2% rise over the same period. For investors, the move raises a specific question: does holding PTC increase the risk of the rest of a portfolio that typically tracks the broader market?
The data suggests PTC adds less market risk than an index fund would. Over the past year of daily moves, PTC moved approximately 0.62% for every 1% move in the S&P 500. On the index's average down day, when the S&P 500 lost 0.61%, PTC lost only 0.55%. Conversely, on the index's average up day, when the S&P 500 gained 0.64%, PTC gained 0.52%. For a holder with $10,000 in PTC stock, this translates to an average loss of about $55 on down days and a gain of about $52 on up days.
However, PTC's overall volatility is far higher than the market's. Over the past year, PTC's volatility was 49.4%, compared to 13.0% for the S&P 500. This disparity indicates that while PTC is less sensitive to daily market fluctuations, its larger price swings stem from company-specific news rather than broad market trends. The correlation between PTC and the S&P 500 was just 0.16 over the past year, where a score of 1 would indicate the stocks moved in lockstep.
With the acquisition agreement in place, future price movements are likely to be driven by news regarding the sale rather than market performance. As of October 5, 2026, PTC stock traded at $192.26, below the agreed-upon cash price of $205 per share. Holders are due this set cash price if the transaction closes, a structure that typically results in smaller price swings than those seen during the previous year.
Longer-term performance metrics show that PTC has not compensated investors for its higher volatility compared to the index. Over the past five years, PTC returned 10.0% annually against the S&P 500's 13.9%. During that same period, PTC's annualized volatility was 35.1%, compared to 17.0% for the index. When return is divided by volatility to measure efficiency, PTC scored 0.28, while the S&P 500 scored 0.82.
For investors who already own other companies that have agreed to be sold for cash, PTC represents a similar type of bet: that a signed sale will successfully go through. While betting on a single stock always carries risk regardless of direction, PTC's current position is defined by its low correlation to market moves and its pending acquisition terms.