Non-financial corporations (NFCs) have acted as vocal and important allies with the financial industry when it comes to advocacy over regulatory policy. Why? We explore this question in the context of the lobbying activity surrounding the financial policy reforms in the USA following the global financial crisis. We propose a range of explanations for why some NFCs might become ‘financial activists’ in support of the financial industry, while others remain passive. We find a wide range of indicators of firm-level financialization to be unreliable predictors of NFC financial activism, in addition to indicators of potential external control by financial firms through ownership or subsidiarization. NFC financial activism appears to be related to how a given firm is embedded in broader structures of corporate networks, relational political action and ideology.