By Telis Demos

Investors in insurance companies have been held back by an unusual amount of uncertainty. Now they have a new benchmark to go by.

Property-and-casualty giant Chubb has outlined its anticipated exposure to the panoply of risks going on right now, including Covid-19 and civil unrest in major cities. In an announcement ahead of its earnings report later this month, Chubb said it estimates a net global catastrophe loss of $1.8 billion for the second quarter.

The bulk of the losses stem from Covid-19. Chubb made only a limited adjustment for the pandemic in the first quarter, citing the evolving and amorphous nature of the crisis--though it did warn the effect would be big. Now it has tallied up about $1.4 billion of pretax claims, including some commercial property and entertainment-related claims such as travel insurance; professional liability; workers' compensation; and credit insurance. On top of what it could specify, Chubb added $100 million to the estimate as an uncertainty buffer. It also expects $184 million in reduced net written premiums due to Covid-19's economic fallout.

As big as this tally is, it likely isn't as bad as the market feared. Given Chubb's typical market share, Ryan Tunis of Autonomous Research estimates the insurer's disclosure implies a roughly $40 billion to $70 billion loss for the industry as a whole due to Covid-19--a bit less than the $80 billion-plus suggested when insurance executives said it could be the biggest loss event in history. Chubb also estimated $130 million in pretax losses related to civil unrest during the quarter.

Investors should note something else in Chubb's announcement. It said it was adding loss exposure of $259 million related to so-called reviver statutes that allow pursuit of civil claims against sexual abusers of children beyond previous time limits. State reviver laws have been cited as one driver of "social inflation," or increasing exposure by insurers to big jury-damage awards. The move here signifies two things: that there will indeed be more losses, but also that insurers will continue to press for higher rates to compensate for this risk.

Investors should wait to see how these same trends play out at other carriers, too, to better judge industry exposure and see who might still be playing catch-up in reserving for social inflation or Covid-19. That includes insurers such as American International Group that have already given some pandemic loss estimates.

But overall, the bar may be raised for earnings season. The S&P 500 property-and-casualty sector is now trading at an average of 1.3 times book, recovering from its slip below book value in March and just off its five-year average of 1.4 times. This suggests a less-scary downside from Covid-19 is already priced in. Investors' focus should now be on whether insurers' pricing and premiums can show signs of possible upside.

Write to Telis Demos at telis.demos@wsj.com