Calpine Corp
Calpine Corporation was a Fortune 500 company based in Houston, Texas. It was the largest generator of electricity from natural gas and geothermal energy in the United States, with operations in competitive power markets. In January 2026, Constellation Energy announced it had completed its acquisition of Calpine for $16.4 billion and that Calpine would become a business unit of Constellation.
What If You Bought CPN Earlier?
Estimate based on split history only. Excludes dividends, fees, taxes, and intraday movement.
Stock Split History
Newest split first. Cumulative multiple = compounded growth from that date to today.
| Split Date | Price Before | Ratio | Split Multiple | Cumulative |
|---|---|---|---|---|
| Nov 14, 2000 | — | 2-for-1 | 2× | 2× |
Calpine Corp Market Cap Timeline
A validated annual market-cap history is unavailable from the current sources. The current market-cap snapshot, when shown above, is not treated as historical evidence. Split markers cover all 1 recorded split. Filled dots have market-cap data for that year; hollow dots mark split years outside market-cap source coverage.
At least two source-validated annual observations are required before this page draws a market-cap timeline. A current snapshot is not treated as historical trend data.