By dividing financial assets into liquid and speculative assets, this paper extends the classical three-stage dynamic model to investigate how financial assets allocations affect corporate financing and investment decisions. Theoretical analysis shows that holding liquid assets lowers leverage and promotes real investment, while allocating speculative assets plays an adverse role. Specifically, the reservoir roles of liquid assets maintain consistent across time horizons, but the substation roles of speculative assets change into reservoir in the long term for providing more capital with higher return on assets. Further, based on the semi-annual nonfinancial listed firms from 2007 to 2019, this paper measures liquid assets and speculative assets with the ratios of financial assets holding and financial profits over total assets, and then the results using the polynomial inverse lag (PIL) approach are consistent with theoretical predictions.