Markets regularly move up and down. Every time the market falls, your SIP buys more units. In case of negative returns, the loss you see is only notional, i.e., it will be real if you decide to sell off your holdings. Hence, it is prudent for investors to continue with their investment plans. Benefits of a SIP are seen over the long term when you keep investing regularly over different market cycles. Continuing to invest when markets are down gives you a better chance to enhance returns when the market recovers.