Overnight funds explained: The safest place to park idle business cash?

Businesses looking to park surplus cash safely eventually run into the same question: is there an option with even less risk than a liquid fund? Overnight funds are usually the answer, built specifically around the idea of holding nothing longer than a day.

What are overnight funds?

Overnight funds are open-ended debt mutual funds that invest exclusively in securities maturing within one business day. At the start of each trading day, the fund's assets consist mostly of cash, which gets deployed into overnight securities that mature by the next business day. The proceeds are then reinvested into new overnight instruments, repeating the cycle daily. This structure is what makes overnight funds one of the lowest-risk categories in the debt mutual fund space, and one of the simplest to understand, since there's no complex duration or credit strategy behind the portfolio.

How overnight funds actually work

Because every holding matures the next day, a fund manager has very little room to take on credit or interest rate risk. There's no long-duration bond sitting in the portfolio that could lose value if rates move. There's no lower-rated issuer being held for extra yield. The entire structure is built around capital preservation and liquidity first, returns second.

Most overnight funds invest in instruments like tri-party repos, government securities, and other overnight-maturity money market instruments. Because these securities settle and mature within a single cycle, the fund's net asset value moves in very small, predictable increments day to day, rather than fluctuating with broader bond market movements the way a longer-duration fund would.

This is also what separates overnight funds from liquid funds, which can hold instruments maturing up to 91 days, and from corporate bond funds, which invest in higher-quality corporate debt with longer maturities and correspondingly higher interest rate and credit risk. The shorter the holding period, generally, the lower the risk and the lower the return.

How safe are overnight funds, really?

Overnight funds sit near the bottom of the risk spectrum in India's mutual fund classification system. Every mutual fund scheme is required to display a risk-o-meter, a SEBI-mandated visual tool that rates schemes across six risk levels, from low to very high, based on factors like credit risk, interest rate risk, and liquidity for debt schemes. Overnight funds typically sit at the lowest end of this scale, which reflects their minimal exposure to both credit and duration risk.

That said, low risk isn't the same as zero risk. No mutual fund investment is completely risk-free, and returns will always run lower than instruments carrying more risk. For a business that genuinely can't afford any volatility on a portion of its cash, that trade-off is usually worth it.

We've covered how overnight funds fit alongside other low-risk instruments here: How to multiply idle cash: Strategies every CFO should know

How overnight funds are taxed

For businesses, gains from overnight funds are taxed as per current debt mutual fund taxation rules, added to total income and taxed at the applicable corporate or business tax slab, since these funds don't qualify for the indexation benefits or preferential long-term treatment that some other categories receive. This is worth factoring into the comparison, since it affects the actual post-tax return a business ends up with, not just the headline yield.

Overnight funds vs. liquid funds vs. corporate bond funds

Mutual fund investments are subject to market risk. Please read scheme-related documents carefully before investing. Past performance is not indicative of future returns.

When overnight funds make sense for a business

Overnight funds work best for a specific kind of cash: surplus where you're genuinely unsure if you'll need it tomorrow, and where any volatility, however small, isn't acceptable. A few common scenarios where this fits well:

• Cash sitting ahead of a known near-term payment, like payroll or a large vendor payment due within days.

• A rolling operating buffer that a business wants earning something without giving up same-day comfort.

• Surplus that just landed and hasn't been assessed yet for a longer-term deployment plan, a safe temporary parking spot while that decision gets made.

We've laid out where overnight funds fit into a broader deployment strategy here: How to deploy idle cash without compromising liquidity

When overnight funds aren't the right fit

If your surplus genuinely won't be needed for a few weeks or longer, overnight funds are usually leaving return on the table. Liquid funds cover that slightly longer horizon with a modest step up in yield and still same-day or next-day redemption. For surplus with an even longer runway, corporate bond funds or other instruments become worth considering, in exchange for accepting more risk. Using overnight funds for all your surplus, regardless of horizon, tends to under-deliver on returns compared to a properly segmented approach.

How to choose an overnight fund

A few things worth checking before picking one:

• Fund size and consistency: Larger, more established overnight funds tend to have more stable day-to-day operations and fewer disruptions during periods of market stress.

• Expense ratio: Since returns are already modest by design, a lower expense ratio matters more here than in higher-yield categories, where a small difference can meaningfully affect net returns.

• AMC track record: Look for a fund house with a consistent history managing debt categories specifically, rather than one where debt funds are a small, secondary part of their business.

• Redemption process: Confirm how quickly funds actually reach your account, most overnight funds process this within one working day, but it's worth verifying with the specific fund house or platform.

Keeping this in context, not as a one-off decision

Overnight funds are one piece of a broader cash strategy, not a replacement for thinking through your full liquidity needs. The right approach usually involves splitting surplus across a few instruments based on time horizon, rather than putting everything into the single safest option available, since that tends to leave meaningful return on the table over a full year.

If figuring out that split isn't something your team has time to revisit regularly, KodoNorth is built to handle Idle Cash Management.

FAQs

1. Are overnight funds completely risk-free?

No. They carry minimal credit and interest rate risk due to their one-day maturity structure, but no mutual fund investment is entirely risk-free.

2. How quickly can I redeem money from an overnight fund?

Typically within one working day, making them one of the most liquid options available.

3. Are overnight funds better than a savings account for idle cash?

Generally yes, in terms of returns, while offering comparable levels of safety and liquidity, though returns will always be modest given the low-risk structure.

4. Should all of my surplus cash go into an overnight fund?

Not usually. Overnight funds suit cash needed on very short notice. Surplus with a longer time horizon is typically better placed in liquid funds or other instruments offering more yield.

5. How are returns from overnight funds taxed for a business?

Gains are added to total income and taxed at the applicable business tax slab, since overnight funds don't qualify for indexation or preferential long-term capital gains treatment.