Just two days of Oprah Winfrey’s Weight Watchers wtw 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:

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%.