Sigma Lithium Corporation (SGML), the Brazilian mining company whose primary listing on the NASDAQ makes it a direct entry point for US retail investors seeking to invest in Brazil, saw its shares drop 4.95% to $10.55 today, continuing a volatile trend in the lead-up to its second-quarter earnings report. The sharp decline in the US-listed equity did not appear to be tied to any specific company-issued news, but rather represents a continuation of technical weakness that has seen the stock struggle over the past month, dipping more than the broader Basic Materials sector.