The launch of the GLD ETF did face some significant setbacks and challenges. One notable setback was the opposition and criticism it received from certain corners of the gold industry. Traditional gold proponents, such as gold dealers and some central banks, were concerned that the ETF's introduction could disrupt the physical gold market and potentially suppress prices.

Another setback was the controversy surrounding the auditing process of the GLD ETF. Some investors and industry experts raised concerns about the transparency and verifiability of the gold holdings. Questions were raised about whether the gold bars held by the ETF were truly allocated and audited on a regular basis. This led to debates about the actual physical backing of the ETF and its ability to deliver on its promise to track the price of gold accurately.

Additionally, the GLD ETF faced regulatory hurdles and had to comply with various regulations and requirements imposed by authorities such as the Securities and Exchange Commission (SEC). These regulations were put in place to ensure investor protection and fair trading practices but added complexity and costs to the ETF's operations.

Despite these setbacks, the GLD ETF has persevered and gained widespread acceptance and popularity among investors seeking exposure to gold. It remains one of the largest and most actively traded gold ETFs globally, with a significant amount of assets under management. Over time, efforts have been made to address concerns and improve transparency, including periodic audits and regular disclosures of gold holdings to enhance investor confidence.