Oprah’s Ad Campaign Is Causing Weight Watchers’ Stock to Soar – by Michal Addady DECEMBER 30, 2015, 5:54 PM EST

It’s up nearly 20% Wednesday.

Just two days of Oprah Winfrey’s Weight Watchers WTW 18.64% ad campaign has caused the company’s stock to soar.

Bloomberg reports that Weight Watchers’ stock went up 7% on Tuesday and 19% on Wednesday, which is the most that it has gone up in one day since Nov. 6. Winfrey purchased a 10% share of the company in October and now sits on the board of directors. Including options, she owns about 15% of the company.

In the commercial, which she posted on Twitter when it debuted Tuesday, she shares her own experience:

Screen Shot 2015-12-31 at Dec 31, 2015 4.25

Since partnering with the weight-loss brand, Oprah has helped the stock more than triple in value. Before she bought it, her 10% stake was worth $43 million. Now, it’s worth about $150 million.

With many different weight loss programs to choose from, Weight Watchers has been struggling in recent years. However, the partnership with Oprah could be what revives the brand: Almost immediately after the partnership was announced, shares jumped more than 90%.