If there's one word you could use to describe the kinds of stocks that Cathie Wood buys, it would be "innovative." In fact, three of her ARK Invest exchange-traded funds (ETFs) include the word "innovation" in their names. 

Some of the ARK Invest portfolio positions that Wood has been adding to lately take innovation to an especially high level. Here are three stocks Wood just bought more of that are absolute game-changers.

1. Beam Therapeutics

Wood's flagship ARK Innovation ETF has loaded up in recent weeks on Beam Therapeutics (BEAM -7.35%). The gene-editing stock currently ranks as the ETF's 18th-largest holding. It's also the ninth-largest position in Wood's ARK Genomic Revolution ETF. 

Beam Therapeutics is a pioneer in base editing. Most types of gene editing involve double-strand breaks in DNA that can cause random unwanted insertions and deletions. Base editing is highly precise, with no double-strand breaks and no off-target genetic changes. Because of these characteristics, base editing holds tremendous promise as a method for developing therapies targeting genetic diseases and "off-the-shelf" cell therapies for treating cancer.

So far, Beam has advanced two base-editing candidates into clinical testing. It's evaluating BEAM-101 as a treatment for two rare blood disorders: sickle cell disease and beta-thalassemia. The company expects to begin dosing patients in a phase 1 study of experimental cancer cell therapy, BEAM-201, by mid-2023.

Those two programs could be joined by two others soon. Beam hopes to submit for regulatory approvals to start clinical studies for BEAM-301 as a treatment for glycogen storage disease type 1a and BEAM-302 as a treatment for severe alpha-1 antitrypsin deficiency by early 2024.

The company has a long way to go. But if its base-editing programs prove to be safe and effective, Beam could be a massive winner.

2. CRISPR Therapeutics

Beam isn't the only gene-editing stock that Wood's ARK Innovation ETF has been buying over the last few weeks. The ETF has also added to its position in CRISPR Therapeutics (CRSP -2.56%). After its latest purchases, CRISPR Therapeutics ranks as ARK Innovation ETF's eleventh-largest position. It's also the seventh-largest holding in the ARK Genomic Revolution ETF.

CRISPR Therapeutics focuses on CRISPR-Cas9 gene editing, a technology that's been hailed as the biggest biotech discovery of the century. The company is one of a handful of leaders working on this promising approach.

Unlike its rivals, though, CRISPR Therapeutics has a huge catalyst on the way with potential regulatory approval of its first program. The company, along with its big partner, Vertex Pharmaceuticals, could win U.S. and European approvals for exa-cel as a functional cure for both sickle cell disease and transfusion-dependent beta-thalassemia as early as late 2023.

In addition to exa-cel, CRISPR Therapeutics' pipeline includes five other clinical-stage programs. It's evaluating cancer cell therapy CTX110 in a phase 2 study, and it has two other experimental cell therapies -- CTX112 and CTX130 -- in phase 1 testing. VCTX210 and VCTX211 are in early-stage testing as potential treatments for type 1 diabetes.

3. Twist Biosciences

ARK Innovation ETF has bought more shares of Twist Biosciences (TWST -2.15%) as well over the last month. Twist is now the No. 21 position in that ETF and the No. 22 position in the ARK Genomic Revolution ETF.

Twist is a leader in making synthetic DNA. In 2022, the company generated revenue of nearly $204 million, up 65% year over year. It's not yet profitable. However, Twist's gross margin continues to improve, rising from 39% in 2021 to 41% last year. 

The company currently makes its money in three key markets. Life sciences researchers use its synthetic biology products. The company's synthetic DNA is also used in next-generation sequencing to help prepare samples. Biopharmaceutical customers use Twist's antibody discovery services and DNA libraries.

Twist is also going after another opportunity that could be highly disruptive. It has developed a way to store data in DNA. The company believes this approach could store massive amounts of data in extremely small volumes with the lowest carbon footprint of any storage media.