Overnight funds — the safest debt fund category

Overnight funds sit at the lowest-risk end of the debt mutual fund spectrum. They invest exclusively in securities maturing the next business day — primarily Tri-Party Repo (TREPS) backed by government securities. The result is a fund category with virtually no interest rate risk, minimal credit risk, and daily liquidity at almost zero volatility.

What overnight funds invest in

SEBI's overnight fund category requires the entire portfolio to have residual maturity of 1 business day. Typical instruments:

• Tri-Party Repo (TREPS): overnight collateralised borrowing arranged through the Clearing Corporation of India. Backed by government securities held as collateral.
• Overnight reverse repo with RBI: very limited use; for very-large funds.
• 1-day government securities (rare given the rolling maturity).

The risk profile is dominated by counterparty risk on TREPS, which is structurally minimal because of the collateralization through CCIL.

Risk profile

• Interest rate risk: virtually zero. A 100 bps rate shift moves the next day's NAV by less than 0.003%.
• Credit risk: minimal. TREPS is collateralized; counterparty failure is unlikely and even then the collateral covers it.
• Liquidity risk: minimal. The fund holds securities maturing next business day.
• NAV volatility: extremely low. Daily NAV moves are tiny.

For comparison, the risk-o-meter rating is "Low" — the lowest possible rating for a mutual fund.

Returns

Historical overnight fund returns:

• Typical range: 5.5-6.5% pre-tax per year.
• Tracks the RBI repo rate closely.
• Slightly below liquid fund returns (which can earn slightly more from 30-91 day instruments).

Cut-off times

Standard SEBI cut-offs apply:

• Purchase by 1:30 PM: same-day NAV.
• Redemption by 3:00 PM: same-day NAV; funds available T+1.

Exit load

Overnight funds carry no exit load. The redemption mechanics are designed for daily flow — no friction.

Where overnight funds excel

Corporate treasury

Companies parking large operating cash positions for very short periods. The combination of safety, daily access, and modest return beats both savings accounts (lower yield) and FDs (broken-deposit issues).

High-net-worth idle cash

HNIs with substantial cash awaiting deployment into longer-term positions or upcoming purchases. Overnight funds give safety with modest yield.

Bridge between events

Awaiting a property purchase, an IPO investment, or a structured product entry — the parking ground for funds that will be deployed within days.

Maximum-safety emergency layer

For very risk-averse investors: replace some of the liquid fund emergency layer with overnight fund for slightly lower yield in exchange for slightly lower risk.

Where they don't excel

• 1+ month horizons: liquid funds typically outperform by 30-50 bps with marginally higher risk.
• Tax efficiency: post-2023 slab taxation makes long-holding less attractive.
• Wealth growth: the 5.5-6.5% return doesn't outpace inflation over years.

Tax treatment

Overnight funds are debt funds. Post-Finance Act 2023:

• Units bought on or after 1 April 2023: gains taxed at slab rate, regardless of holding period.
• Units bought before 1 April 2023: previous regime applies (LTCG with indexation above 36 months).

Liquidity flow during stress

During periods of money-market stress (e.g., the 2018 NBFC crisis, March 2020 liquidity squeeze), overnight funds typically held up better than longer-duration debt categories. Their structural design — instruments maturing daily — means they don't need to liquidate positions at depressed prices to meet redemptions.

Comparison to liquid funds

Position sizing

For most retail investors, overnight funds aren't strictly necessary — liquid funds cover the same use cases with slightly better yields. They become relevant for:

• Investors with very large cash positions (₹50 lakh+) seeking maximum safety.
• Treasury managers and corporate users.
• Investors at periods of money-market stress when the next 25 bps of yield isn't worth the marginal credit / liquidity risk.

Operational considerations

• SIP into overnight funds is technically possible but uncommon — typically you make a lumpsum purchase from a holding.
• Most AMCs allow same-day or next-day setup of standing instructions for daily / weekly transfers (effectively automating cash sweep).
• Some banks now offer "sweep accounts" that automatically move idle savings balance into overnight or liquid funds.

Holding-period optimization

Because the post-2023 tax is at slab rate regardless of holding period, there's no LTCG advantage to holding overnight funds long. Use them for the duration they're needed; redeem when the cash is required for deployment.

Choosing between funds

Within the overnight fund category, differences between funds are small. Look for:

• Direct plan (lower expense than Regular).
• Larger AUM (typically lower expense and more stable management).
• AMC reputation and operational reliability.

The actual portfolio composition is similar across overnight funds because the instrument set is narrow.

The structural minimum

Overnight funds represent the structural minimum-risk category in the mutual fund universe. Anyone seeking lower risk than this should be in a savings account, not a fund. The minor return advantage of overnight funds over savings does not always justify the extra step for very small amounts (₹1-5 lakh).