What it means
The ratio has two halves. Available stable funding, or ASF, weights each source of money by how likely it is to stick around, and required stable funding, or RSF, weights each asset by how hard it would be to sell or how long it will stay on the books.
The weightings encode a simple view of behaviour. Equity and long-term borrowing score 100% because they are not going anywhere, ordinary retail deposits score 90% to 95% because savers rarely move in a panic, and short-term wholesale funding from other financial institutions scores nothing at all.
On the asset side the logic reverses. Cash and central bank reserves require no stable funding, high-quality government bonds require very little because they can be sold instantly, and long-dated residential mortgages require a great deal because they cannot be turned into cash quickly.
The rule was introduced under Basel III after the 2008 crisis, when several banks failed despite appearing profitable, simply because they had funded long assets with overnight money that stopped being offered. Its companion measure, the Liquidity Coverage Ratio, deals with a 30-day stress; the NSFR deals with the structural, one-year picture.
For non-bank readers the practical effect shows up in pricing. Because long-term lending now demands expensive stable funding, banks price multi-year facilities and committed undrawn lines higher than they once did, and they favour customer deposits over market borrowing when funding growth.
In practice
Real-world examples.
Example
A bank planning to grow its mortgage book by $5 billion calculates that the new loans will add $5bn x 65% = $3.25 billion of required stable funding. It launches a fixed-term savings product rather than borrowing short term in the money markets.
Example
A treasury team notices its NSFR has slipped to 103% after a large corporate depositor withdrew funds. It issues $2 billion of three-year senior bonds, which attract a 100% ASF factor, and restores headroom before the quarterly regulatory return.
Example
A commercial borrower is quoted a higher arrangement fee for a five-year committed facility than for a rolling one-year line. The bank explains that undrawn long-term commitments still consume stable funding under the rules, which feeds directly into the price.
Think of it
“NSFR is the abbreviation for Net Stable Funding Ratio-your one-year funding stability measure.
Formula
Calculation
NSFR = Available Stable Funding / Required Stable Funding, and must be at least 100%
Consider an illustrative bank with $105 billion of assets, funded as follows. Equity of $8 billion at a 100% ASF factor gives $8 billion. Stable retail deposits of $40 billion at 95% give $38 billion. Less stable retail deposits of $10 billion at 90% give $9 billion. Wholesale funding with more than one year to run of $12 billion at 100% gives $12 billion. Short-term wholesale funding of $35 billion at 0% gives nothing.
Total Available Stable Funding = $8bn + $38bn + $9bn + $12bn = $67 billion.
Now the assets. Cash and central bank reserves of $6 billion at a 0% RSF factor require nothing. Government bonds of $10 billion at 5% require $0.5 billion. Residential mortgages of $70 billion at 65% require $45.5 billion. Corporate loans maturing within a year of $14 billion at 50% require $7 billion. Other assets of $5 billion at 100% require $5 billion.
Total Required Stable Funding = $0 + $0.5bn + $45.5bn + $7bn + $5bn = $58 billion.
NSFR = $67 billion / $58 billion = 1.155, or 115.5%, comfortably above the 100% minimum.Case study
Seen in the real world.
Ashford Union Bank is an entirely fictional, illustrative retail bank created to show how the ratio bites in practice. It had built a profitable business writing long-dated buy-to-let mortgages funded largely by three-month deposits from other financial institutions, a strategy that looked cheap while short-term rates stayed low.
In this illustrative scenario the funding mix scored badly. Ashford's mortgages consumed a large amount of required stable funding while its three-month interbank borrowing counted for none, leaving the ratio at 94% against a 100% minimum and putting the bank in breach.
The remedy took eighteen months and cost real money. Ashford launched a two-year fixed savings product priced 0.7 percentage points above its previous cost of funds, issued $1.5 billion of five-year senior debt, and slowed new mortgage lending by roughly a third for three quarters. The ratio recovered to 108%, margins narrowed, and the illustrative moral is that cheap funding is only cheap until a regulator prices in the risk that it disappears.
Watch out
Common mistakes.
- Treating the NSFR as a measure of solvency. It measures funding structure over a year, not whether assets exceed liabilities.
- Confusing it with the Liquidity Coverage Ratio. That ratio tests survival through a 30-day stress, while the NSFR tests the structural one-year funding profile.
- Assuming all deposits count equally. Sticky retail savings attract high ASF factors while short-term deposits from financial institutions attract none.
Questions
People also ask.
Why is 100% the minimum rather than a higher number?
The rule is designed to stop structural mismatch rather than force banks to over-fund, and most banks in practice run a buffer above the floor.
Does the NSFR apply to non-bank companies?
No, it is a banking regulation, although the underlying principle of matching long assets with long funding is sound for any business.
How does it affect what customers pay?
Long-dated and committed facilities consume more stable funding, so banks generally price them higher than short-term revolving credit.
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