MPLX LP (MPLX) is slightly undervalued and Williams Cos Inc (WMB) is overvalued.
Against our estimates of intrinsic value, MPLX trades at the wider discount: a margin of safety of +16%, against -182% for WMB.
Values as of the 22 Sept 2026 close.
Discounting its cash flows at 7.7% (average of 3 methods) values the shares at $70.27; the price of $59.16 is 16% below that value, and 81% of that value comes from beyond year five.
Leak Score 69/100 on 9 of 12 signals
Discounting its cash flows at 7.9% (average of 2 methods) values the shares at $25.17; the price of $70.98 is 182% above that value, and 80% of that value comes from beyond year five.
Leak Score 38/100 on 10 of 12 signals
| Metric | MPLX | WMB |
|---|---|---|
| Verdict | Slightly undervalued | Overvalued |
| Price | $59.16 | $70.98 |
| Intrinsic value | $70.27 | $25.17 |
| Margin of safety | +16% | -182% |
| Leak Score | 69/100 (9/12) | 38/100 (10/12) |
| Market cap | $60.0B | $86.8B |
| Revenue growth, 5 years | 6.8% | 8.9% |
| Operating margin | 38.8% | 38.0% |
| Net margin | 39.3% | 24.9% |
| Return on equity | 33.9% | 24.0% |
| Debt to equity | 1.86 | 2.33 |
| P/E | 12.7x | 28.3x |
| Forward P/E | 12.3x | 27.6x |
| P/B | 4.3x | 6.6x |
| Dividend yield | 7.7% | 3.0% |