CNBC's "Mad Money" host Jim Cramer is making the case for banks again, and he's not being subtle about it. In a post on X Tuesday, Cramer declared that "the banks are all cheap," then went a step further by identifying one stock as "the cheapest of all" with the "most upside" in the group.

Capital One Gets The Spotlight

That stock would be Capital One Financial Corp. (COF), the sixth-largest bank in the United States based in Virginia. Cramer said he's been backing this name for quite some time, noting that he's stuck with his bullish call "for 60 points" as the stock has climbed.

The timing is interesting. Capital One just wrapped up its massive $35.4 billion acquisition of Discover Financial Services earlier this year, a deal that's expected to unlock meaningful synergies going forward. Beyond that headline number, the bank is sitting on $56.92 billion in excess capital, which gives it plenty of firepower for share buybacks and other capital returns.

But here's what really catches your eye: Capital One trades at just 10.91 times forward earnings. To put that in perspective, let's look at how it stacks up against the rest of the banking heavyweights.

Even with a solid 29.15% gain year-to-date, Capital One trades at the lowest valuation multiple in this group. Every other major bank carries a higher price-to-earnings ratio, which is essentially what Cramer is pointing to when he calls it the cheapest.

Wall Street Is Coming Around

Cramer isn't alone in his enthusiasm. Several major Wall Street firms have warmed up to Capital One in recent weeks. Wolfe Research just initiated coverage with an "Overweight" rating and a $270 price target earlier this week, implying 16.97% upside from current levels.

Citigroup (C) analysts went even further, reiterating their "Buy" rating while bumping their price target from $275 to $290. That represents a potential 25.64% gain from where the stock is trading now.

The broader banking sector has been on a tear this year, and there's a clear catalyst behind it. Major banks sailed through the 2025 Federal Reserve stress test with capital to spare, which opened the floodgates for about $100 billion in shareholder returns through dividends and buybacks. When regulators give you the green light and your balance sheet is fortress-strong, returning cash becomes the obvious move.

Capital One (COF) shares closed Tuesday up 0.09% at $230.81, then added another 0.52% in after-hours trading. The stock ranks high on momentum indicators, showing favorable price trends across short, medium, and long-term timeframes.

So here's the setup: a bank that just completed a transformative acquisition, sitting on a mountain of excess capital, trading at the sector's lowest valuation, with Wall Street analysts raising their targets. Whether that adds up to Cramer's "most upside" claim is something the market will ultimately decide, but the pieces are certainly in place for Capital One to keep marching higher.