CMA accounts are attracting more people looking for a place to park payroll between paydays or keep emergency funds. The advantage of earning daily interest is common to all CMAs, but the right selection criterion is not the yield number on the first screen. What matters is where that yield comes from — which instrument the securities firm uses to invest your money differs by account type, and that is where collateral and deposit protection diverge. This article compares the four types — RP, promissory note, MMW, and Jongeum (综合金融, comprehensive finance) — using publicly available data.
How a CMA Pays Interest — Starting with the Structure
A CMA is a demand deposit account opened at a securities firm. As explained by BankSalad, the securities firm invests funds deposited by customers in various short-term financial instruments on their behalf and returns the gains as interest. Interest is calculated and accumulated daily — by the same guide, depositing 1 million won at a 3% annual rate earns approximately 82 won per day. The gap with bank demand deposit rates, which sit around 0.1%, is significant when it comes to managing funds in transit.
Because of this structure, distinguishing CMA types is essentially distinguishing "what it invests in." According to Toss Bank's summary, the RP type invests in bonds such as government and public bonds; the promissory note type invests in promissory notes issued by the securities firm itself; and the MMW type invests in short-term products of high-credit financial institutions. The Jongeum type offered by comprehensive finance companies adds a fourth track.
Among these, the MMW type has relatively strict operating rules. Based on BankSalad's summary, it is a variable-rate type managed through Korea Securities Finance Corporation, requires a separate agreement, and withdrawals made between 5:00 PM and 8:00 AM the following day do not earn interest for that day. In contrast, RP and promissory note types offer a fixed agreed rate and are easy to understand structurally — and are the default options presented in most securities firm apps. This is why most comparisons focus on these two types.
RP Type vs. Promissory Note Type — The Rate Difference Is a Collateral Difference
The difference between the two most commonly compared types lies in collateral. Based on BankMall's summary, the RP type is managed through repurchase agreements (RP) collateralized by high-quality bonds such as government and special public bonds. With collateral backing the structure, it is straightforward and highly stable. The promissory note type invests in promissory notes issued directly by the securities firm — without collateral, it relies solely on the firm's credit, and offers a higher stated yield in return. As of the October 2025 examples cited by BankMall, RP types were around 2.2–2.4% annually and promissory note types were around 2.5–2.8% — since rates change frequently, the absolute figures are less important than reading the gap structure between the two types.
| Type | Investment Target | Collateral | Deposit Protection |
|---|---|---|---|
| RP type | High-quality bonds (government/public) via repurchase agreement | Yes | Not applicable |
| Promissory note type | Securities firm-issued promissory notes | None (firm's credit) | Not applicable |
| MMW type | Short-term products of high-credit financial institutions | — | Not applicable |
| Jongeum type | Short-term financial products of comprehensive finance companies | — | Applicable |
Ultimately, the additional yield on the promissory note type is not free — it is the price of unsecured risk. Whether to accept that price is a judgment call that depends on the size of the deposit and the securities firm's credit.
Deposit Protection — Only the Jongeum Type Qualifies
Of the four types, only the Jongeum type is covered by deposit protection. The RP, promissory note, and MMW types are not, meaning — as BankSalad explains — there is a possibility of principal loss in the extreme scenario of the securities firm going bankrupt. As compared by Toss Bank, this contrasts with bank and savings bank parking accounts, which are protected up to 100 million won per depositor under deposit protection. The Jongeum type is offered by companies licensed for comprehensive finance operations and is the only one of the four types under the umbrella of the Deposit Protection Act — but access is limited because few institutions offer it. That said, no protection does not mean high risk. The RP type has high-quality bond collateral backing it, and the promissory note business itself is a licensed operation permitted only to large, qualified securities firms. Structurally, reading it as "one step up the risk ladder from a bank deposit" is accurate.
A CMA's higher rate is the compensation for climbing one rung up the risk ladder above a bank deposit — the height of that rung differs by type.
This is why a purpose distinction is needed. For small, rapidly cycling funds such as payroll in transit or spending money, a CMA's daily compound interest is advantageous; for lump sums that absolutely cannot be lost, dividing the funds between the Jongeum type or a bank parking account with deposit protection and a CMA makes structural sense. Either way, "how much of this money is protected" comes first, and rate comparison comes after — that is the proper order for this product category.
What to Watch
CMA rates are not fixed conditions — they move with the market. Even after choosing an account, the following items require periodic review.
- Benchmark rate direction — CMA rates track short-term rates. If the benchmark rate is cut, today's rate should not be assumed to continue; if a hold or hike cycle continues, this assumption breaks down
- Your account type — confirm whether it is an RP type or promissory note type on the enrollment screen; rates differ by type even within the same securities firm
- Conditions and duration of preferential or promotional rates — determine whether the high number on the first screen is a limited-amount, time-limited promotion or a base rate
- For promissory note type, the securities firm's financial condition — since the structure is unsecured, the issuer's creditworthiness is effectively the collateral
- Deposit size — check whether the amount placed outside deposit protection is at a manageable level and whether the allocation with protected accounts makes sense
- Interest payment method — confirm in the product disclosure whether interest accumulates daily, or whether conditions such as the MMW type's loss of same-day interest for certain withdrawal times apply
