What happened

Pharmaceutical behemoth Pfizer (PFE 0.91%) is having another bad day today. The drugmaker's shares plunged by a jaw-dropping 9.5% right out of the gate Monday morning. While Pfizer's stock has regained some of this lost ground as today's trading session has unfolded, its shares are still down by 4.4% as of 1:11 p.m EDT Monday afternoon.

The pharma titan's stock has now lost almost 20% of its value since the start of 2020. On the bright side, Pfizer's shares have outperformed the Dow Jones Industrial Average so far this year. 

A businessman biting his fingernails.

Image source: Getty Images.

So what

Pfizer's stock seems to be plunging today mainly from the issues emanating out of China due to COVID-19. In brief, China reportedly experienced a sharp economic contraction during the first quarter of 2020, thanks to the government's implementation of extreme quarantine measures starting in January.

The tie-in to Pfizer is that the drugmaker has been generating a fair amount of drug sales in this key emerging market over the past several quarters, especially for its older legacy medicines. With China on lockdown over the past two months or so, Pfizer seems destined to report a noticeable decline in international pharmaceutical sales when the company announces first-quarter earnings later this year.  

Now what

Is Pfizer a bargain buy on this sharp pullback? Pfizer's dividend now stands at an eye-popping 4.65%, it has a strong balance sheet, a top-notch branded drug portfolio, and an elite clinical pipeline. The company also announced a five-point plan last Friday to engage in an industrywide collaborative effort to accelerate the development of both a vaccine and antiviral treatments indicated for COVID-19. So, if you can ride out this short-term volatility, Pfizer's stock is arguably worth buying right now.