Like all companies, banks finance their assets by equity and debt. Alan Grenspan enacted in the 80s Tier 1 ratio Rule for the banking system: the amount of capital must be greater than 8% of the total debt, its inverse is the leverage to be less than 12.5.
After the financial turmoil he increased this ratio to 10%, i.e. a leverage of up to 10.
After the bursting of the Internet bubble, Alan Grenspan dictated to companies to recognize any goodwill in losses and in full instead of amortizing it over 20 years, which restored fundamentals and GDP growth.
These two rules must be applied to determine the current real leverage of real capital: tangible assets (excluding minority interests).
Table of real leverage ratio and Tier 1 for 28 Systemically Important Financial Institutions (SIFIs),
Document 1:
None of these major banks respects the rules of a real Tier 1 ratio above 10%but U.S. banks are those that are closest, Citigroup and Wells Fargo are the most reliable,
Document 2:

Banks in the United States in blue, French Gos banks in red, Switzerland’s banks in orange, banks under Bank Of England in light green, other European bank in dark green s, Asian banks in… yellow.
The graph shows that European banks leverage is the most dangerous, especially Crédit Agricole and Deutsche Bank,
Document 3:

Major European banks fail to meet prudential borrowing. The interbank market in the euro zone does not work. The ECB has to replace the market to avoid a banking tsunami that threatens the world.
| Rank | Banks 2012 Q4 | Liabilities | Tangible equity | Leverage | Tier 1 |
|---|---|---|---|---|---|
| 1 | Citigroup | 1 706,43 | 158,23 | 10,8 | 9,3 |
| 2 | Wells Fargo | 1 310,32 | 112,644 | 11,6 | 8,6 |
| 3 | Goldman Sachs | 874,583 | 64,417 | 13,6 | 7,4 |
| 4 | Morgan Stanley | 729,446 | 52,927 | 13,8 | 7,3 |
| 5 | Bank of America | 2 061,76 | 148,212 | 13,9 | 7,2 |
| 6 | BBVA Bilbao | 596,43 | 41,43 | 14,4 | 6,9 |
| 7 | State Street | 208,179 | 14,403 | 14,5 | 6,9 |
| 8 | Bank of China | 11 951,98 | 791,703 | 15,1 | 6,6 |
| 9 | JP Morgan Chase | 2 221,41 | 137,736 | 16,1 | 6,2 |
| 10 | Standard Chartered | 588,564 | 35,867 | 16,4 | 6,1 |
| 11 | Unicredit Group | 918,286 | 50,866 | 18,1 | 5,5 |
| 12 | HSBC | 2 515,41 | 136,929 | 18,4 | 5,4 |
| 13 | Bk New York Mellon | 341,702 | 17,288 | 19,8 | 5,1 |
| 14 | Mitsubishi UFJ FG | 213 916 | 10 555 | 20,3 | 4,9 |
| 15 | ING Bank | 1 116,91 | 51,718 | 21,6 | 4,6 |
| 16 | Royal Bk of Scotland | 1 317,20 | 59,699 | 22,1 | 4,5 |
| 17 | Banque Populaire CE | 1 101,22 | 46,305 | 23,8 | 4,2 |
| 18 | Santander | 1 219,60 | 50,028 | 24,4 | 4,1 |
| 19 | Sumitomo Mitsui FG | 137 268 | 5 623 | 24,4 | 4,1 |
| 20 | Nordea | 651,865 | 25,555 | 25,5 | 3,9 |
| 21 | BNP Paribas | 1 839,24 | 68,054 | 27 | 3,7 |
| 22 | UBS | 1 219,80 | 39,434 | 30,9 | 3,2 |
| 23 | Barclays PLC | 1 444,96 | 45,359 | 31,9 | 3,1 |
| 24 | Mizuho FG | 166 301,70 | 5 181,50 | 32,1 | 3,1 |
| 25 | Credit Suisse | 896,944 | 27,243 | 32,9 | 3 |
| 26 | Société Générale | 1 214,06 | 36,636 | 33,1 | 3 |
| 27 | Deutsche Bank | 1 973,80 | 38,2 | 51,7 | 1,9 |
| 28 | Crédit Agricole SA | 1 813,55 | 28,814 | 62,9 | 1,6 |