1. 一級資本 Tier1
銀行的普通股股份、保留盈餘，可轉換債券等等視為 Tier 1資本。若資產規模2500億美元以上 或 海外曝險部位100億美元以上之銀行，會有被要求一定比例。
因為普通股股份、保留盈餘是投資人無法請求贖回的，所以也被當作是核心資本。
基本上可以想成該銀行或金融機構的自有資本佔整體資產比例越高，代表該銀行基本體質越好。是基本體質，並非絕對沒有風險喔，衡量風險尚須其他觀察因子。
2. 補充槓桿率SLR-Supplementary Leverage Ratio
08年的危機基本上從銀行開始，故監管機構設定這個目標在大型銀行之上。
這個目標是什麼呢？
就是剛剛所說的Tier 1除以資產必須要大於3%。
而資產不只是資產負債表中的資產，還要加上表外，例如衍生性金融商品的曝險、預計潛在的承諾放款、自營部位的融資等等，都當作公式中的分母。
3. 強化補充槓桿率eSLR-Enhanced Supplementary Leverage Ratio
而大型銀行中，有些夠大，大到不能倒，不然會動搖國本的銀行，被稱為「系統性重要銀行」。
這些銀行因為夠重要，就不能只是3%，要更高，例如至少5%。
所以，股東出資必須要高、盈餘必須要更多保留一部分在股東權益項目之內。當然，也會有一些額外的Benefit，例如發行新金融商品、承作國家債券交易等項目。
也就是「類」國家隊的意思。
監管機構之所以設計SLR 與 eSLR 標準，並不是要限制銀行放貸，而是要銀行在擴大資產，或承作更複雜的業務時，有足夠的「核心自有資本」作為後盾與保護。
透過這個制度，就是為了在下一次金融風暴來臨前，為市場投資者與存款人提供更高一層保護。
——————以下翻成英文—————
Tier 1 Capital
For banks with total assets exceeding USD 250 billion or foreign exposure over USD 10 billion, components such as common equity, retained earnings, and certain convertible bonds are recognized as Tier 1 capital.
Because common equity and retained earnings cannot be redeemed by investors, they are considered core capital—the most stable and loss-absorbing form of capital.
In simple terms, the higher the proportion of a bank’s own capital to its total assets, the stronger its fundamental financial condition. (Of course, “stronger” doesn’t mean risk-free.)
SLR – Supplementary Leverage Ratio
The 2008 financial crisis largely began in the banking sector, prompting regulators to impose stricter requirements specifically on large banks.
One such requirement is the Supplementary Leverage Ratio (SLR), which mandates that a bank’s Tier 1 capital must be at least 3% of its total leverage exposure.
Importantly, “total assets” in this context doesn’t just refer to on-balance sheet assets. It also includes off-balance sheet exposures such as derivatives, potential commitments to lend, and financing exposures from trading activities—all of which are included in the denominator of the formula.
eSLR – Enhanced Supplementary Leverage Ratio
Among large banks, some are so big and interconnected that their failure could destabilize the entire financial system. These are known as Global Systemically Important Banks (G-SIBs).
Due to their critical importance, these banks are subject to even higher leverage requirements—not just 3%, but typically at least 5%.
This means shareholders must contribute more capital, and the bank must retain a larger portion of its earnings as equity capital. In return, these institutions may enjoy additional benefits, such as the ability to:
Issue more innovative financial instruments Participate in government bond trading and market-making operations
In a way, they function as part of the quasi-sovereign financial infrastructure.
Why SLR and eSLR Matter
The purpose of SLR and eSLR is not simply to limit lending, but to ensure that when a bank grows its balance sheet or engages in more complex activities, it maintains a strong buffer of core capital.
These frameworks are designed to serve as early safeguards—to protect both the market and depositors long before the next financial crisis strikes.
