Why BlackBerry Ltd., Textura Corp., and iShares MSCI Turkey Tumbled Today

Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

Investors happily added riskier assets to their portfolios today, selling safer investments like bonds as the 10-year Treasury yield hit 3% for the first time since 2011. Fears about interest rates didn't hold major stock market indexes back, but some stocks missed out on the post-holiday rally. BlackBerry , Textura , and iShares MSCI Turkey were among the laggards on Thursday.

BlackBerry dropped 9% as former CEO Michael Lazaridis officially ended his quest to buy out the company he helped found. Instead, he started selling off his position in the mobile-device maker, with SEC filings from Tuesday showing sales of 3.5 million shares, cutting his position to 26.3 million shares. The move comes as a major about-face for investors who had seen Lazaridis' willingness to buy the company as a sign of its continued viability, and even last week's announcement of an extended relationship with Foxconn doesn't seem like any guarantee of BlackBerry's future prospects.

Textura plunged 17% as the construction-industry software maker was the latest target of a negative report from Citron Research. The report [opens PDF] includes various allegations of fraudulent behavior and material misrepresentations, as well as criticism of Textura's business, arguing that its flagship software product has only limited value. Citron concludes that the stock's value is closer to $4 -- about 90% below the stock's closing price Tuesday. Textura responded to the report by rejecting any allegation of fraud, collusion, or deception in its IPO and subsequent filings with the SEC. As with most negative reports, it'll be interesting to see whether Citron's allegations pan out in the long run.

iShares MSCI Turkey fell 7%. The country-tracking ETF suffered from allegations of corruption among Turkish Prime Minister Recep Tayyip Erdogan's cabinet members. Erdogan fired four of his ministers, and announced changes for up to 10 positions, sending the Turkish currency to a new record low, and sending the country's stock market index to its lowest level in more than a year. The move reminds U.S. investors that political risk is an important consideration in any international investment, and with continuing unrest likely, it could be a while before shares start to rebound.