Prosperity Cashes the Check It Wrote Two Years Ago — and Suddenly Prefers Its Own Stock to Other People's Banks

Prosperity Cashes the Check It Wrote Two Years Ago

For six straight quarters, Prosperity Bancshares has been telling anyone who would listen the same thing: the net interest margin is going from 2.75% to 3.70%, just wait. On Wednesday it stopped waiting. Tax-equivalent NIM came in at 3.73% for Q3 2026, up 49 basis points year over year and 26 linked-quarter — and the CFO, Asylbek Osmonov, reaffirmed the 3.73%-3.75% exit rate for Q4 and the 3.80%-3.85% average for 2027 that he first laid out in July. “for 2027, we said 3.80. I think it is still for whole year, 3.80, 3.85” — Asylbek Osmonov, Chief Financial Officer · 2026-07-29 was the July version. Nothing changed. That is, in a sector famous for sandbagging and silent re-guides, the story.

The roll-up finally shows up in the numbers

Total assets reached $54.1 billion, up 41%; loans $32 billion, up 45%; deposits $41 billion, up 48%. Those are not organic numbers — they are American Bank, Texas Partners and Stellar Bank landing on the balance sheet in a single year. American's operational integration completed in September; Texas Partners converts in November; Stellar in March 2027.

The reported quarter looks ugly and isn't: a 62.1% efficiency ratio, but only because $69.7 million of merger expense ran through it. Strip that out and the efficiency ratio is 48%, net income $200 million, EPS $1.67. The picture will keep changing: management guided Q4 non-interest expense to $235-238 million and a clean run rate of $220-225 million per quarter once Stellar converts — implying another $65-70 million of pre-tax savings still to come. Given the $54 billion asset base, that is a real number, not a rounding exercise.

The fundamentals block still shows the pre-merger shape — the latest 10-Q covers the period ending 2026-07-31, with deposits of $32.6 billion and loans of $20.9 billion. The call adds roughly $8.4 billion of deposits and $11 billion of loans in ninety days. The loan-to-deposit ratio on that stale snapshot was 64%; David Zalman put the post-merger figure at 77%, against an internal policy ceiling of 85%.

The Fed flipped — and Prosperity was already leaning into it

Here is the cleanest contrast in the whole tape. In October 2025, Zalman was certain a hike was off the table: “I think the Trumpster put this new guy in, Walsh, and he is not gonna raise rates in my opinion.” — David E. Zalman, Chief Executive Officer · 2026-07-29 This quarter the CFO said the opposite, without ceremony: “we did increase our deposit rates at the end of the third quarter due to the, you know, Fed rate increase.” — Asylbek Osmonov, Chief Financial Officer · 2026-10-28 The Fed rate hike is now a live global theme — it ranked third in the market's curated keywords this quarter — and Prosperity, a self-described "neutral to asset-sensitive" balance sheet, is positioned for it rather than ambushed by it.

The nuance is where the money is. The bank raised money-market rates roughly a quarter point, from 2.75% to 3.00%, and concentrated the increase on balances of $1 million and up. Cost of deposits steps up only 6-7 basis points in Q4, total cost of funds about 8. Because the vast majority of the franchise is genuine core deposits, the deposit beta stays low and the repricing of the bond portfolio — $2.2 billion of annualized cash flow, 5.92% current book yield versus purchases at 5.5%-7.5% — keeps doing the heavy lifting. That is the entire Prosperity model in one paragraph, and it is why the rising rate environment analysts keep asking about is a tailwind here rather than the squeeze it is at many regional peers.

Which is also why management's refusal to give a higher NIM number reads as discipline rather than weakness. Analyst Janet Lee essentially asked: with the belly of the curve where it is, why not better than 3.80%-3.85%? The answer: the model held rates flat. “there might be a you know, possibility to do better, but, you know, us being conservative, we just gonna stick to our guidance that we provided.” — Asylbek Osmonov, Chief Financial Officer · 2026-10-28

An acquirer that suddenly likes its own stock more

This is the genuinely new note. Prosperity's identity for two decades has been the consolidator. This quarter the President and COO said, plainly: “in the near term, buybacks way more likely than acquisitions.” — Kevin J. Hanigan, Chief Banking Officer · 2026-10-28 And the CEO attached a price trigger: “when we are trading less than 10x earnings, we probably make more money buying our stock back than really buying somebody else.” — David E. Zalman, Chairman and Chief Executive Officer · 2026-10-28

The 10x earnings line is not new rhetoric — Zalman said almost exactly the same thing in July. What is new is that the M&A machine has been explicitly put in maintenance mode while two conversions finish: "our focus is truly the combination of Stellar Bank and Texas Partners." A $54 billion bank trading at 0.9x tangible book with $850-880 million of projected 2027 earnings and roughly $300 million of dividends has obvious arithmetic on its side. Management floated $600 million of excess capital generation.

I think that delivers in spite of what is likely to be a flat kind of loan growth year. that is gonna deliver double digit. In fact, low to mid teen double digit EPS growth for 2027 even with flat.

That is the central claim of the call: low-to-mid-teens EPS growth in 2027 with flat loans, then 3%-5% loan growth in 2028 as the acquired portfolios finish running off, producing a second consecutive double-digit year.

What is not growing — and what management will not buy

Credit is fine and management knows it. Non-performing assets rose to $194 million, or 60 basis points of loans, largely acquired paper. There was no provision. The allowance sits at roughly 3x NPAs. Zalman was almost flippant about the NPA optics: “At the size that we are at, I do not ever see us really getting below $100 million in nonperforming... we will probably settle at about $125 million to $150 million.” — David E. Zalman, Chairman and Chief Executive Officer · 2026-10-28

The genuine soft spot is origination. Mortgage warehouse averaged $1.229 billion for the quarter but had slid to $1.11 billion by late October, with Q4 guided to $850-900 million on rates plus seasonality. Energy lending in West Texas is stable but dormant — customers with nine figures of cash who rarely draw. And the whole sector's loan-pricing problem has not gone away: out-of-state entrants bidding large credits at spreads this bank will not touch, which is exactly why it declines to chase loan growth.

The banks that you know, that use financial engineering to make their numbers look better. Peter turns out well. You sell and reposition and put a new market value in the next week... I do not see any.

So the arc of this report is simple. Prosperity closed three deals at once, hired the balance sheet that was always going to arrive, hit a margin target it had promised for over a year, and then looked at its own core deposit growth machine and its own 0.9x book multiple and decided the next best acquisition is itself. The thing to watch next is not the loan book — it is whether Q2 2027 shows the $220-225 million clean expense run rate and whether Texas Partners and Stellar convert without the deposit attrition this management has spent a year warning about.