Lesson 9 of 20 · 8 min
The forced-sale multiple: why selling a dollar does not cure a dollar
Selling collateral to fix a shortfall shrinks the collateral, so the cure costs more than the gap.
This is the lesson people most often have never seen, and it is pure arithmetic. When you repay a shortfall by selling pledged securities, the sale does two things at once: it reduces your balance, and it reduces your collateral. Both sides of the ratio move. That is why a $13,000 shortfall is not cured by selling $13,000 of stock.
Work the algebra once and it will stay with you. Let S be the amount of collateral sold. After the sale the balance is B − S and the collateral value is V − S. You need that ratio to equal the threshold t. Solving gives a formula whose shape is the whole lesson: the denominator is (1 − t), which is small when the threshold is high, which makes S large.
S = (B − t × V) ÷ (1 − t)
- S
- Collateral you must sell to bring LTV exactly back to the threshold.
- B
- Current loan balance, including accrued interest.
- V
- Current collateral value on the basis your agreement uses.
- t
- The maintenance threshold as a decimal. A higher t makes (1 − t) smaller and S larger.
The ratio S divided by the raw shortfall is the forced-sale multiple, and it equals 1 ÷ (1 − t). At a 70 percent threshold the multiple is 3.33. At 75 percent it is 4. At 80 percent it is 5. So an $80,000 gap at an 80 percent threshold requires selling $400,000 of stock. The multiple is a property of the threshold alone, which means it is knowable in advance, before anything goes wrong.
The multiple explains why forced sales feel disproportionate. They are disproportionate — by exactly 1 ÷ (1 − t).
Key terms
- Forced-sale multiple
- How many dollars of collateral must be sold per dollar of shortfall. Equals 1 ÷ (1 − threshold).
- Shortfall
- The amount by which your balance exceeds what the threshold permits at current collateral value.
- Self-defeating cure
- The general problem that fixing a ratio by shrinking both its numerator and denominator requires a larger action than the gap suggests.
Worked example
A $13,000 shortfall and a $43,333 sale
Balance $300,000, collateral value $410,000, threshold 70%.
- Permitted balance
- $287,000
- Shortfall
- $13,000
- Forced-sale multiple
- 3.33×
- Collateral to sell
- $43,333
- Check: after the sale
- $256,667 ÷ $366,667 = 70.0%
$410,000 × 0.70
1 ÷ (1 − 0.70)
($300,000 − 0.70 × $410,000) ÷ 0.30
The gap was $13,000. The sale was $43,333 — more than three times the number that appeared in the notice.
Check yourself
Balance $500,000, collateral value $600,000, threshold 80%. How much must be sold, and what is the multiple?
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Educational only. Nothing in this lesson is investment, legal or tax advice, or a recommendation to enter into any transaction. Figures are illustrative and computed from the inputs stated in the lesson.