The biggest risk associated with SIPs is that your average cost of investments (NAV) will tend to be higher in bull markets, and even minor corrections in stock prices can result in losses. For example, let's say you started investing in mutual fund SIPs in April 2020. The market had had a steep correction due to the covid fears but swiftly recovered and went up a lot since then. But since SIP investments happen in monthly installments, you would accumulate at higher and higher prices as the market went up, so the average cost would be relatively higher than if you invested in a lump sum in April 2020. As a result, this correction phase that we are going through would've hurt you more than it wound for a lumpsum investor.
SIPs are most beneficial in flat or bearish markets.