With markets rallying, you might be thinking about how to prepare for what may be ahead. I'm talking about the next bull market. We don't know exactly when it will arrive, but bear markets always have led to these periods of growth. And here's some even better news: Bull markets generally last much longer than bear markets, offering your portfolio time to recover from any losses and grow.

So, what should you do today to plan for this exciting market time? Buying shares of promising growth companies that haven't yet benefited from the rally is a terrific idea because, right now, you can pick up many of these players for a bargain. Let's check out two dirt-cheap stocks that could rocket higher when the market takes off.

An investor in a home office smiles while talking on the phone.

Image source: Getty Images.

1. Teladoc Health

Teladoc Health's (TDOC -3.59%) revenue and number of visits soared in the triple digits in the early days of the pandemic as patients favored virtual medical visits over going to a doctor's office. Later into the health crisis though, Teladoc saw a slowdown in growth, and at the same time its purchase of Livongo, a chronic care specialist, set it back from its goal of profitability. As a result, the shares plummeted.

But things are looking much brighter today. The company started this year seeking to balance growth with attaining profitability and so far has managed to drive significant earnings before income, taxes, depreciation, and amortization (EBITDA) and free-cash-flow growth with a lower rate of sales growth than in the past. That's as Teladoc has cut costs, invested cautiously, and maximized efficiency.

In the most recent quarter, the company's results met or surpassed guidance, and since earlier in the year, EBITDA and free cash flow have also beat expectations. And in the quarters ahead, growth may come more easily as expenses linked to the acquisition of Livongo decrease.

Meanwhile, Teladoc has seen growth in demand in key areas, such as whole person care -- the idea of addressing all of a person's medical needs -- and chronic care. Chronic care is particularly important because nearly half of Americans suffer from at least one chronic illness.

So Teladoc has made significant progress this year, but one problem remains: the share price. It's lost more than 25% since the start of the year. In response, Teladoc has launched an operational review of its business to become even more efficient in order to favor profitability and share-price performance.

Today, Teladoc is trading for its lowest ever in relation to sales -- a rock-bottom price considering the company's bull market potential.

TDOC PS Ratio Chart

TDOC PS Ratio data by YCharts.

2. Intellia Therapeutics

Intellia Therapeutics (NTLA -3.83%) is working in the exciting field of CRISPR gene editing, a technology that involves "fixing" faulty genes responsible for disease. Just recently, another company using the technique, CRISPR Therapeutics, won the world's first regulatory authorization -- in the U.K. -- for a CRISPR-based treatment. This is a positive development for others in the field because it shows regulators are willing to OK products relying on this new, cutting-edge technology.

And since CRISPR companies often work in different treatment areas, one company's approved product doesn't necessarily represent competition for another company's product.

Intellia recently reached a big milestone, becoming a "late-stage" drug-development company when regulators gave it the green light to begin a phase 3 trial. It aims to start this trial in patients with transthyretin amyloidosis with cardiomyopathy (ATTR) by the end of the year. In this genetic disease, a misfolded protein impacts organs including the heart and kidneys.

Intellia is also approaching the late-stage mark with another candidate. This one is for the rare disease hereditary angioedema (HAE), a disorder involving severe and unpredictable swelling. The company aims to complete enrollment of its phase 2 HAE trial this quarter.

These treatments could be particularly sought after if they reach commercialization because, by editing disease-causing genes, they represent potential cures for diseases that, today, have limited treatment options.

Intellia shares have dropped about 11% this year but in recent weeks have started to rebound. Still, they're far from their record high when there was much less visibility on the company's future. This looks like a bargain for a stock that could skyrocket in a bull market.