Identifier: C3T8L1 · Revision: 2026-10-26 · Classification: restricted

Decision and objectives

Calculate securities-credit financing and account equity. The decision record must connect the exposure, cash dates and implementable contract, rather than stop at a favorable price forecast.

By the end, you can calculate securities-credit financing and account equity; distinguish debt from a loss-limited purchase; stress a supplied collateral policy without treating it as a live legal ratio.

Prerequisite: C3T4L6; completed Classes 1 and 2 and the Stock Market School foundation or Forex School foundation. All cases below are hypothetical; their prices, costs, rates, dates, contractual assumptions and collateral amounts are teaching inputs, not current offers.

Mechanics

A securities-credit purchase combines an owned security with a loan from an authorized intermediary. The investor receives price changes and eligible distributions but owes principal, interest and charges. The lender can have collateral and liquidation rights. A debt remains after a security loss; financing does not turn the purchase into an option.

SPK Serial V No 65 supplies the regulatory framework, while temporary decisions and the customer contract can affect requirements. Every ratio below is explicitly hypothetical; none is a current statutory or broker minimum.

Price and return drivers

Simple interest = loan principal × annual decimal rate × days/day basis. Equity = eligible asset value − loan − accrued charges. The teaching equity ratio is equity/market asset value; the actual legal account calculation and eligible assets must be checked. Interest accrues even if the share price is unchanged.

Worked case

Buy hypothetical shares for TRY 200,000 using TRY 120,000 own cash and TRY 80,000 loan. Finance 30 days at 45% actual/360: interest TRY 3,000. Sell for TRY 220,000, with TRY 400 total trading charges and TRY 100 custody. Net cash after loan and interest = 220,000 − 80,000 − 3,000 − 400 − 100 = TRY 136,500; profit over initial cash TRY 16,500, or 13.75% before tax. Loan repayment is not itself an expense; interest is.

Adverse case

If shares fall to TRY 150,000, equity after interest and the same charges is TRY 66,500; loss on initial cash TRY 53,500. Under a supplied hypothetical 50% equity-ratio trigger, equity before trading/custody charges is 150,000 − 80,000 − 3,000 = TRY 67,000, below required TRY 75,000: cash top-up TRY 8,000. Cash is assumed to repay debt here; buying more shares changes the denominator and is not the same cure. A gap below debt can leave a deficit after liquidation.

Practical use

Confirm the intermediary's current credit permission, instrument eligibility, loan rate reset, interest basis, collateral, call timing and liquidation charges. Use dated issuer measures and current SPK/Borsa decisions. Read borrowing capacity as an offer limit, not evidence that the trade fits the investor. Include funding tax or levies only after checking investor and transaction facts; no live tax schedule is supplied here.

Reconcile the confirmation, position register and cash statement separately. Costs include the quoted bid/ask spread, brokerage and clearing charges, collateral or principal financing, currency conversion, custody where relevant, and exit or termination charges. A mark is not a fill. Any amount explicitly excluded below remains outside the reported result. Tax is excluded from these teaching cases: an actual comparison requires income year, investor residence and individual/corporate status, contract and acquisition dates, settlement form and effective law. The GIB guide, checked 2026-10-26, covers 2025 individual investment income, so its publication date alone does not settle a 2026 derivative liability.

Decision boundaries

Credit fits only when the investor can service debt through a price decline and rate reset. Dividends may be reduced and do not guarantee interest coverage. If a future cash need forces sale after a drawdown, an unfinanced smaller holding can meet the objective more reliably.

Practice and references

Exercise: hypothetical loan TRY 50,000, 36% actual/360, 20 days. Calculate interest, equity ratio and cash repayment needed under the supplied 45% trigger. Solution: interest = 50,000 × 0.36 × 20/360 = TRY 1,000. Assets worth TRY 90,000 leave TRY 39,000 equity before other costs; ratio 39,000/90,000 = 43.33%. With the supplied 45% teaching trigger, cash repayment of TRY 1,500 restores equity to TRY 40,500; it does not create profit.

Takeaway: Stress a supplied collateral policy without treating it as a live legal ratio using the actual cash schedule, with every excluded cost and remaining exposure stated.

Reference card: securities-credit. Formula: Simple financing cost. Glossary: Securities credit, Equity ratio. Next lesson: C3T8L2. Topic test.

Sources and verification date (2026-10-26):

Shared reference guide