SMJ International Holdings shares fell 24.2% Friday after the Singapore-based flooring specialist said it could not determine the cause of unusual market activity. The company issued a statement under Section 401(d) of the NYSE American Company Guide, saying it had made inquiries but could not determine whether corrective action was appropriate. SMJ said it was unaware of any material nonpublic information or undisclosed business developments that would explain the trading. The company distributes carpet tiles, broadloom carpets and vinyl tiles under its proprietary SMJ brand in Singapore and more than 20 countries, primarily in Asia, including environmentally certified flooring products.