In the Democratic presidential debate earlier this month, Vermont Sen. Bernie Sanders, who supports breaking up giant financial institutions, reiterated his belief that the three largest U.S. banks “are much bigger than they were when we bailed them out.”

The debate had barely finished when I received an email from an industry supporter who decried Sanders’ claim as myth, but who selectively picked a few journalist quotes to back up the argument. In an industry where financial statistics abound, it is bizarre how often data is conveniently omitted in discussions about the true size of banks and their risks.

Using stats from the Office of the Comptroller of the Currency, I compared data for Bank of America, Citibank, JPMorgan Chase and Wells Fargo at the end of 2007 with numbers from the second quarter of this year. Sanders is absolutely correct. Citibank grew 6%, Bank of America grew 22%, JPMorgan grew 49% and Wells Fargo grew more than 230% (primarily due to its acquisition of Wachovia).

It is true that JPMorgan’s asset size did decline by 6% between the first and second quarters of this year. However, claiming that it is shrinking is analogous to saying a dieter is shrinking after losing a couple of pounds in a week. If JPMorgan and the dieter continue to shed assets for a few quarters, then we can certainly analyze the numbers to establish whether it is a trend.

But banks are even bigger than Bernie Sanders may realize.

When talking about “too big to fail,” bank lobbyists and journalists are largely silent about banks’ enormous amounts of off-balance sheet assets. The U.S. accounting standards, defined by the Generally Accepted Accounting Principles, let banks exclude a significant number of items such as certain derivatives from their books. Institutions can omit them where credit, market, operational, and liquidity risks are difficult to identify. The resulting opacity forces market participants to become forensic accountants, needing to use magnifying glasses to pour through hundreds of footnotes in the hopes of piecing together the true size of a bank and its risks.

Under U.S. GAAP, derivatives are measured on a “net” basis, which arguably undercounts the total. But international accounting standards are more stringent and more inclusive. For example, a 2013 analysis by the Milken Institute’s James R. Barth and Apanard Angkinand Prabha found that when “derivatives are calculated under” International Financial Reporting Standards “JPMorgan’s assets double to about $4 trillion.” This moves JPMorgan from the seventh largest bank to the largest globally.

Unfortunately, new rules from the Dodd-Frank Act still allow the use of some off-balance sheet accounting. U.S. accounting rules permit corporations and banks to exclude their full derivatives’ exposures from their financial statements. They only report “fair value” changes in those derivatives over time. This is akin to a borrower disclosing only the changes in his or her debt over time rather than actual debt levels.

For anyone who is worried about Sen. Bernie Sanders being a socialist, it’s too late: socialism is already thriving on Wall Street. Banks cannot claim that they are true free market advocates when they benefit enormously from opacity, and when they accepted bailouts from taxpayers who never benefited from the industry’s off-balance sheet transactions.

If investors could see the true size and level of banks’ risks, they could instill discipline on the industry by selling their securities. The Securities and Exchange Committee must require that financial statements disclose everything upfront rather than including key holdings only in footnotes. If analysts, the media, and legislators want to do society a service, they should compel banks to lift the heavy veil covering their off-balance sheet activities and models. Otherwise, taxpayers will always be at risk and a true free market will remain a dream.

Mayra Rodríguez Valladares is Managing Principal at MRV Associates, a New York based capital markets and financial regulatory consulting and training firm.