MBIN vs ONB: Which Is the Better Buy in 2026?

Same yardstick, side by side (as of September 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.

The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. MBIN and ONB share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.

This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined MBIN and ONB exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.

Merchants Bancorp (NASDAQ: MBIN), headquartered in Carmel, Indiana and founded in 1990, is a bank holding company that runs three segments: Multi-family Mortgage Banking (originating and servicing government-sponsored FHA multi-family, healthcare, and bridge/construction loans), Mortgage Warehousing (funding agency-eligible residential loans and commercial lines for non-depository lenders), and Banking (retail, commercial, agricultural, SBA, and correspondent residential mortgage banking). This mix makes it less like a plain community bank and more like a specialized housing-finance and warehouse lender that has grown total assets to a record of roughly $20.3 billion.

Full MBIN guide

Old National Bancorp (NASDAQ: ONB) is the holding company for Old National Bank, a super-regional bank headquartered in Evansville, Indiana, with a large operational base in Chicago and a footprint concentrated across the Midwest. Following its May 2025 acquisition of Bremer Bank, the company holds roughly $70 billion in total assets and more than $30 billion in wealth assets under management, making it among the top 25 banking companies headquartered in the United States and one of the largest commercial banks in the Midwest. Like most banks, it earns money in two broad ways: net interest income, the spread between what it earns on loans and securities and what it pays on deposits (roughly $2.4 billion on a full-year 2025 basis), and noninterest fee income from wealth management, mortgage banking, treasury management, and capital markets.

Full ONB guide

Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.

• MBIN drivers: Multi-family and healthcare finance niche; Balance-sheet growth and scale.
• ONB drivers: Growth through acquisition and scale; Solid margin and cost discipline.

A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: MBIN's loan-to-deposit ratio has climbed to roughly 124 percent, forcing reliance on external wholesale funding that now approaches 30 percent of gross loans, which raises funding cost and liquidity risk. For ONB, old National is sensitive to interest rates: net interest income (about $2.4 billion in 2025) is its largest revenue line, so falling rates, deposit repricing, or an inverted yield curve can compress the margin and earnings.

Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick MBIN if you believe its drivers more; ONB if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the MBIN and ONB guides.

MBIN. Q1 2026 net income of roughly $67.7 million (about $1.25 per diluted share) rose around 16 percent year over year and came in ahead of consensus, with revenue up about 20 percent to roughly $175 million. The stock trades near 11 times earnings, a discount to broad-market averages that reflects funding and credit concerns. Tangible book value per share of about $38.55 and a low payout ratio leave capital available to fund continued loan growth.

ONB. Reading a regional bank means looking past a single earnings number to a few structural metrics. The net interest margin (around 3.65% in Q4 2025) shows how profitably the bank lends relative to its funding costs, and the efficiency ratio (an adjusted ~48.8% for 2025) measures how lean the operation is, where lower is better. Note the gap between GAAP EPS of $1.79 and adjusted EPS of $2.21, which reflects one-time merger and integration charges from the Bremer deal, so the adjusted figure is a cleaner read on underlying run-rate earnings. A trailing P/E near 13 is in the typical range for regional banks, which tend to trade at lower multiples than the broader market because their earnings are cyclical and rate-sensitive. The distinctive feature here is the growth-by-acquisition scale-up; the open question is how much of the Bremer benefit is already reflected in the share price versus still to be realized through integration.

Headline figures (approximate, JULY 2026): MBIN shows market cap ~$2.1B, revenue (q1 2026) ~$175M, net income (q1 2026) ~$67.7M, diluted eps (q1 2026) ~$1.25; ONB shows revenue (net interest income + fees, fy2025) ~$2.9 billion, net interest income (fy2025) ~$2.4 billion, net income to common (fy2025) ~$653 million GAAP (~$809 million adjusted), diluted eps (fy2025) $1.79 GAAP ($2.21 adjusted).

MBIN and ONB are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined MBIN and ONB exposure against your real portfolio. It is not an investment adviser.