Securities-Backed Loan Calculator
Model how much you can borrow against a portfolio, how close that gets you to a margin call, and what it costs — this year and over time.
LTV Trajectory Vs. Maintenance Threshold
Borrowing Vs. Selling — Year 1
Year-By-Year Detail
| Year | Portfolio | Loan Balance | LTV | Interest |
|---|---|---|---|---|
| 1 | $535,000 | $16,050 | 3.00% | $1,445 |
| 2 | $572,450 | $33,224 | 5.80% | $2,990 |
| 3 | $612,522 | $51,599 | 8.42% | $4,644 |
| 4 | $655,398 | $71,261 | 10.87% | $6,413 |
| 5 | $701,276 | $92,299 | 13.16% | $8,307 |
| 6 | $750,365 | $114,810 | 15.30% | $10,333 |
| 7 | $802,891 | $138,897 | 17.30% | $12,501 |
| 8 | $859,093 | $164,670 | 19.17% | $14,820 |
| 9 | $919,230 | $192,247 | 20.91% | $17,302 |
| 10 | $983,576 | $221,754 | 22.55% | $19,958 |
How A Securities-Backed Line Of Credit Works
An SBLOC lets you borrow against the value of your investment account instead of selling holdings. Because nothing is sold, you don't trigger capital gains — but you take on a floating-rate loan secured by assets whose value can fall.
Loan-To-Value And Margin Calls
Your loan-to-value ratio is the loan balance divided by the portfolio value. Lenders set a maintenance requirement — the maximum LTV they allow. If markets drop enough that your LTV crosses that line, the lender can demand you add cash or sell holdings, often at the worst possible time.
The cushion figure above shows how far your portfolio can fall before that happens. A smaller draw relative to your portfolio buys a much larger cushion.
Borrowing Vs. Selling
Borrowing costs interest every year for as long as the balance is outstanding. Selling costs tax once. Over short horizons borrowing often looks cheaper; the longer the balance stays open — and the higher the rate — the more that advantage erodes.
Disclaimer: This calculator provides a simplified estimate for educational purposes only. It is not lending, tax, or investment advice. Actual maintenance requirements, rates, and lending limits vary by brokerage and holdings.