A cohort move, not a merger trade

The five North American Class I railroads — the continent's largest long-haul freight networks — have moved together over the past year, and the pattern undercuts the tidiest version of the merger-arb story. Canadian National (CNI), Canada's largest railway with no acquisition optionality of its own, gained 36.1% over the trailing year — more than Norfolk Southern (NSC), the Eastern U.S. carrier that is the actual target of Union Pacific's pending takeover, which rose just 20.7%. Canadian Pacific Kansas City (CP), the only railroad running a single continuous line from Canada to Mexico and likewise free of deal speculation, gained 20.9%, tying NSC for the cohort's weakest return. CSX, the Eastern U.S. railroad widely discussed as a future BNSF target, led the group at 41.8%, while Union Pacific (UNP), the Western U.S. carrier and the actual acquirer in the pending merger, added 31.6%. All five gained further over just the past 30 days, between 2.6% and 7.4%, and CSX has held a continuous uptrend — its 50-day average above its 200-day — since April 17, roughly 106 days.

The growth is real

Underneath the price action, revenue is genuinely expanding. CNI's second-quarter revenue rose 11.2% year over year with an earnings beat, Gurufocus reported, though its operating ratio — the share of revenue consumed by operating costs — widened 50 basis points to 62.2% on fuel-cost pressure. CPKC's revenue rose 13% with adjusted earnings per share up 13%, the company reported, though its operating ratio also worsened 90 basis points. UNP runs an industry-leading 59.9% adjusted operating ratio, and CSX grew operating income 20% to $1.25B in the first quarter. Sector-wide freight data corroborate a genuine, if uneven, cycle: total U.S. carloads rose 3.1% and intermodal units 3.6% for the year through mid-July, even as coal carloads — a structural decliner — fell roughly 8% year over year.

But the price has moved further than the earnings

That growth has not stopped every multiple from running above its own history. CSX trades at 30.6x trailing earnings; the user's own notes flag that a P/E near 27x "already prices much of the optionality" tied to BNSF-takeout speculation. NSC's 27.9x trailing multiple compares with a standalone-justified 18-20x per the same notes — several turns of pure acquisition premium. CNI trades at roughly 24.2x trailing and 20.6x forward earnings, about 17% above its own historical median; CP sits near 27-28x trailing and 22x forward, about 19% above its own median. UNP's 24.1x trailing multiple already reflects the merger base case, per prior desk notes. The pattern holds across merger names and non-merger names alike — this is a sector re-rating, not just a deal premium.

The catalyst that could still swing it

The Surface Transportation Board accepted UP-NS's amended application on May 28, 2026, and the companies filed supplemental customer-protection commitments on July 27, 2026, but the target close has stretched from early to mid-2027. Opposition includes BNSF, 24 senators, and two rail unions, versus six unions that have signed support agreements. Separately, Buffett told CNBC that BNSF was not shopping for another railroad, knocking CSX down more than 6% even though its uptrend has otherwise held.

The setup

Where it stands — The cohort is up roughly 30% over a year on genuine revenue growth, but every name's forward multiple sits above its own historical median. Would confirm — Continued double-digit revenue growth and stable operating ratios at CNI and CP next quarter, absent any merger link. Would invalidate — STB rejection, a delay past mid-2027, or deepening carload/coal declines that outpace pricing gains. Watch next — STB evidentiary and environmental review, with a statutory decision window roughly 12 months from the May 28, 2026 acceptance. Valuation — CSX 30.6x trailing; NSC 27.9x vs a standalone-justified 18-20x; CNI 24.2x trailing/20.6x forward; CP 27-28x trailing/22x forward — all above own medians.