I don't know how long it will take stocks to recover from the massive market crash. I don't know if the market will plunge another 10% or more. No one does (even if they act as if they do). 

But what I do know is this: There are a lot of stocks that are great picks to buy right now if you're a long-term investor. Some investors might prefer to snatch up stocks with dividend yields that are sky-high thanks to the market meltdown. Others might want to add some dirt cheap bargains to their portfolios. 

If you like growth stocks, there are also plenty of great opportunities. Here are my top growth stocks to buy while the market crash continues.

$1 bill folded into an arrow that is pointing up

Image source: Getty Images.

1. Guardant Health

Liquid biopsies will likely change the landscape of cancer diagnosis and treatment in the not-too-distant future. Instead of requiring surgical removal of tissue for a biopsy to be conducted to determine if a person has cancer, liquid biopsies are blood tests that identify fragments of DNA broken off from tumor cells. The approach holds the potential to enable the detection of cancer at very early stages when treatment can often be more effective. And the leader right now in liquid biopsies is Guardant Health (GH -3.00%).

The company currently markets two products. Guardant360 is used to determine the most effective therapy option for advanced-stage cancer patients, while GuardantOMNI is used by drugmakers to screen patients for clinical trials of experimental cancer drugs. The potential market for Guardant360 in the U.S. alone is around $6 billion. By comparison, Guardant Health's revenue totaled a little over $214 million last year.

But the opportunity for Guardant Health that really fires me up is with its LUNAR liquid biopsies. LUNAR-1 can be used to select neoadjuvant and adjuvant treatments for early stage cancer patients and monitor for cancer recurrence. LUNAR-2 targets the early detection of cancer. The two products aren't commercially available yet, but LUNAR-1 is available for research and investigational use. LUNAR-2 is being evaluated in a clinical study that could lead to FDA approval.

The addressable annual market for these liquid biopsies tops $45 billion. Guardant Health won't claim all of this market for itself. There are other companies vying to develop and launch their own products. But I think Guardant Health will be a huge winner.

2. Square

If you've bought a product from a small- to medium-sized merchant, you've probably used Square's (SQ 2.88%) credit card reader. What you might not realize is that Square has built an ecosystem for merchants that help them conduct business more easily on several fronts, including payroll, point of sales, and marketing. These products and services make Square essential for many small and medium-sized businesses.

Even if you haven't used Square's credit card reader, you might have used the company's Cash App for peer-to-peer payments. Cash App is already a $1 billion-plus business for Square and continues to grow at an impressive rate. It's also highly profitable, contributing 27% of Square's overall gross profit last year.

Square stock has been hit hard by the coronavirus pandemic. Many small retailers have closed as their customers stay home. However, this should only be a temporary crisis for these businesses and for Square. And it presents an opportunity for investors to buy the stock at a discounted price.

Over the long run, the "war on cash" appears to be an unstoppable trend. People across the world are abandoning paper money in favor of credit cards and digital payments. Square stands to be a key beneficiary from this trend.

3. The Trade Desk

The Trade Desk (TTD 3.16%) is surfing the waves of two major trends -- the shifts to digital ads and a transition to programmatic ad buying. The company provides the leading software platform for advertising agencies to buy digital ads programmatically. 

The shift to digital ads isn't just related to advertising on websites. Actually, the most important growth driver for The Trade Desk is connected TV (CTV) thanks to the increased popularity of internet TV streaming services. The Trade Desk CEO Jeff Green calls this a "once-in-a-lifetime consumer shift."

But the transition to programmatic ad buying is also key to the company's growth. In the past, ad agencies purchased ads after negotiating back and forth with media outlets. The Trade Desk enables these agencies to buy ads instantaneously and more cost-effectively.

Fears that businesses would cut back on advertising during the COVID-19 outbreak have weighed on The Trade Desk's shares. However, a surge in streaming TV usage while people are cooped up at home also increases the audience for companies that continue to advertise. Regardless of what impact the pandemic has on The Trade Desk's revenue temporarily, though, the stock appears to be poised for tremendous long-term gains.