The US Securities and Exchange Commission (SEC) is actively working with applicants of spot Bitcoin Exchange-Traded Funds (ETFs) to guide them through the final stages of amendments before potential approval. This engagement is evident from the frequent updates to the S-1 filings made public.Recently, BlackRock submitted an updated S-1 application for its spot Bitcoin ETF, which has sparked discussions and speculations within the Bitcoin community. Some experts interpret this as the SEC’s implicit demand for a ‘kill switch’ in Bitcoin ETFs.The concern arises from a significant change in the language of BlackRock’s S-1 filing. The amendment implies severe consequences if Bitcoin is classified as a security in the United States. It suggests that such a classification would make it challenging to trade, clear, or custody Bitcoin, potentially impacting its market value and liquidity.This perspective is supported by the BlackRock S-1 amendment itself, which states that any SEC or state securities regulator action asserting Bitcoin as a security would have a material adverse impact on its trading value and the shares of the ETF. The document draws a parallel with the case of XRP and Ripple Labs, where SEC action led to a significant drop in XRP’s market capitalization.Caitlin Long, CEO of Custodia Bank, connected this update to a legislative move in New Jersey proposing to define all virtual currencies sold to institutional investors as securities. This raises questions about whether this language is a ‘hidden’ poison pill inserted by the anti-Bitcoin crowd into the ETF documents.According to a reliable source, the contentious language in the S-1 filings was specifically requested by the SEC. This suggests that the inclusion of risk disclosures may be a compliance measure in response to SEC directives. Similar language appearing in other ETF applications further indicates the SEC’s involvement in shaping these disclosures.It remains unclear whether this language serves as a ‘kill switch’ or is simply part of the legal requirements. At the time of writing, BTC traded at $43,692.