Sen. Elizabeth Warren is making the rounds to promote her new book, A Fighting Chance. In addition to dispelling speculation about a presidential bid in 2016, the Massachusetts Democrat and former Harvard law professor continued to make a case for greater government intervention in the financial sector.

On PBS Newshour May 19, 2014, Warren said there’s a need to "break up these banks," which have only gotten bigger since the financial collapse.

"You know, you talked about during the financial crisis we were told these banks are too big to fail," Warren said. "Today, the five largest financial institutions are 38 percent bigger than they were back in 2008, when they were too big to fail."

We found several other instances of Warren giving out this stat, and we thought it was worth a review.

Doing the math

Warren’s office said the anaylsis came from SNL Financial, a private bank researching firm, and they pointed us to a CNN article describing the report. It found assets from the top six banks were up 37 percent. That's six banks, not five, as Warren said, and the article was from September 2013, so it's a little outdated. Therefore, we decided to do the math ourselves.

As we dug in, we realized there are two ways to interpret Warren’s statement. Was she comparing the current top five banks with their pre-recession size? Or was she comparing today’s top five to 2008’s top five?

We decided to analyze it both ways.

Here’s what we found when we looked at the top five banks in 2013 (the latest available data) and the top five of 2008 (we went with reported assets in the middle of the year, i.e. before Congress passed the bank bailout).

Top five banks of 2013

Bank Total Assets JPMorgan Chase & Co. $2,415,689,000,000 Bank of America Corporation $2,104,995,000,000 Citigroup Inc. $1,880,382,000,000 Wells Fargo & Company $1,527,015,000,000 Goldman Sachs Group, Inc. $911,585,000,000 Total $8,839,676,000,000

Top five banks of 2008

Bank Total Assets Citigroup Inc. $2,100,385,000,000 JPMorgan Chase & Co. $1,775,670,000,000 Bank of America $1,723,269,816,000 Wachovia Corporation $812,443,000,000 Taunus Corporation Featured Fact-check Democrats and Joe Biden “want to abolish the suburbs altogether by ending single-family home zoning.” $659,772,000,000 Total $6,411,757,816,000

If you do the math, the top five from the end of 2013 have 38 percent more assets than the top five banks of 2008. That would back up Warren’s claim.

But let’s look at it the other way and compare today’s top five to their 2008 holdings. That gets us a different result.

Bank Total Assets in 2013 Total assets in 2008 JPMorgan Chase & Co. $2,415,689,000,000 $1,775,670,000,000 Bank of America Corporation $2,104,995,000,000 $1,723,269,816,000 Citigroup Inc. $1,880,382,000,000 $2,100,385,000,000 Wells Fargo & Company $1,527,015,000,000 $609,074,000,000 Goldman Sachs Group, Inc. $911,585,000,000 $884,587,000,000* Total $8,839,676,000,000 $7,092,985,816,000

*Before 2009, Goldman Sachs was an investment group, not a bank holding company, so the data was not available through the Federal Reserve. The 2008 figure is taken from their in-house annual report .

There’s still significant growth in those banks, but it’s about 25 percent, not 38 percent. It’s held back by Citigroup, which actually has fewer total assets than it did in 2008.

Being in the top five doesn’t necessarily equate to "too big to fail," even though Warren seemed to imply as much. For example, Wachovia was a top five bank in 2008, and it no longer exists. It was absorbed by Wells Fargo during the fallout of the crisis.

Warren’s comment "presumes simply that there is a threshold ‘too big to fail’ size, and implies that the top five having gotten bigger, they were already past that threshold, and (now) are even more ‘too big to fail,’ " said Satya Thallam, director of financial services policy at the American Action Forum, a center-right think tank. "The size of financial institutions is not per se evidence of ‘too big to fail’ expectations." Other experts we spoke with echoed that sentiment.

There are also other ways to measure bank size, such as total deposits, said Hester Peirce, a senior research fellow at the Mercatus Center at George Mason University.

"These are very tricky comparisons to make," Peirce said. "There’s not a clear way to measure how size has changed."

How they got so big

Warren does not mention how the banks grew, which experts we spoke with said is critical context.

Let’s go back to the Wachovia/Wells Fargo example. In 2008, Wells Fargo was the sixth-largest bank, just outside Warren’s arbitrary cutoff. So a significant reason the top five have grown so much is from that one transaction, where two massive banks become one.

And Wells Fargo/Wachovia is just one example. Lawrence White, a professor of economics at New York University, noted that Bank of America absorbed Merrill Lynch, which, at the end of 2007, had more than $1 trillion in assets, and JPMorgan Chase took on Bear Stearns, a top 15 financial institution before its collapse.

During the financial crisis, the federal government was "desperate to have these banks merge," Peirce said.

"That is a large contributing factor (in the growth of the top five)," she said. "I don’t think that’s the only thing that’s going on, but that’s one of the things that’s going on."

That’s not to say these weren’t controversial decisions. Warren, for the record, opposed those efforts and has said they have made the "too big to fail" issue worse. But understanding how it happened is critical to forming an opinion on what the numbers actually mean.

Peirce also said consolidation and growth among the top banks are not a new trend. In 2001, the five largest banks held about 27.5 percent of all assets; today it’s closer to 47 percent with the sharpest increases coming before the financial collapse.

Our ruling

Warren said, "the five largest financial institutions are 38 percent bigger than they were back in 2008, when they were too big to fail." Without fully understanding where her math was coming from, we had to find our own way to measure this. One way seemed to back her up in a narrowly defined time frame. A different method produced a lower number, though the trend is the same.

Our experts took some issue with her loose characterization of "too big too fail" and some of the context she left out. But her underlying point is largely accurate.

We rate her comment Mostly True.