Consumer signups for Obamacare insurance plans topped 600,000 in the first week of the 2018 open enrollment period, offering a positive sign for insurers uncertain whether Republicans will dismantle the setup.

The Department of Health and Human Services' Centers for Medicare & Medicaid Services said that from Nov. 1 through Nov. 4, a total of 601,642 people selected plans in 39 states that use the federal website HealthCare.gov. Of those, 137,322 -- more than one in five -- were new customers.

During the first week of open enrollment for 2018, more than 200,000 consumers selected plans on the first day, which is more than double the number who signed up on the first day last year, according to a report in the Washington Post that cited unnamed federal officials.

Despite what appeared to be good news for insurers in uncertain times, a number of major healthcare stocks pushed lower Thursday.

Anthem Inc. (ANTM) dipped 0.82% to $215.10 in late-afternoon trading Thursday. Aetna Inc. (AET) dropped 1.8% top $172.33. Centene Corp. (CNC) dropped 0.57% to $92.62 and Molina Healthcare Inc. (MOH) dropped 0.1% to $76.51. The Healthcare SPDR ETF (XLV) slid 0.18% to $81.57.

Outlier HCA Healthcare Inc. (HCA) gained 0.42% to $79.20.

More of What's Trending on TheStreet:

More from Life Insurance

How to Protect Yourself and Your Family From Long-Term Care Insurance Scams

How to Protect Yourself and Your Family From Long-Term Care Insurance Scams

Why Property & Casualty Insurance Should Not Be Optional

Why Property & Casualty Insurance Should Not Be Optional

Seven Common Financial Regrets You Want to Avoid

Seven Common Financial Regrets You Want to Avoid

Could Walmart Be the One to Disrupt Healthcare?

Could Walmart Be the One to Disrupt Healthcare?

Why Going to Urgent Care Is Better Than the ER

Why Going to Urgent Care Is Better Than the ER