Commerce Secretary Wilbur L. Ross Jr. shorted stock in a shipping firm — an investment tactic for profiting if share prices fall — days after learning that reporters were preparing a potentially negative story about his dealings with the Kremlin-linked company. The transaction, valued between $100,000 and $250,000, took place last fall after Mr. Ross became aware that journalists investigating offshore finances were looking at his investments in the shipper Navigator Holdings, whose major clients included a Russian energy company. The New York Times emailed a list of questions about Navigator to Mr. Ross on Oct. 26. Three business days later, Mr. Ross, a wealthy investor, opened a short position in Navigator, according to filings released on Monday by the Office of Government Ethics. The company’s stock price slid about 4 percent before Mr. Ross closed his position on Nov. 16, eleven days after the articles were published by The Times and the International Consortium of Investigative Journalists as part of the “Paradise Papers” project.