The paper approaches the modeling of the yield curve from a stochastic volatility perspective based on time deformation. The way in which we model time deformation is new and differs from alternatives that currently exist in the literature and is based on market microstructure theory of the impact of information flow in a market. We model the stochastic volatility process by modeling instantaneous volatility as a function of trade intensity in the spirit of Russell and Engle (1998). One contribution of the paper therefore lies with the introduction of a new transaction level approach to the econometric modelling of stochastic volatility in a multivariate framework exploiting intensity-based point processes previously used by Bowsher (2003), Hall and Haustch (2003). The strength of intensity-based modeling lies with the ability to update the information set at every point in time, which is crucial in the multivariate case. We have tested the time-deformation hypothesis and found that the yields to maturity of U.S. treasury notes and bonds are driven by different 'operational clocks' or 'information sets' but are related to each other by a common 'operational clock' captured by the cross-excitation effect of trades in the multivariate Hawkes model. Diagnostic tests have shown that the point process model is relatively well specified and robustness test using realized volatility exhibit the structural soundness of the intensity-based volatility. We have also provided a link to derivative pricing by showing the mathematical derivation of caplet prices using the intensity-based instantaneous volatility under the HJM framework. The model can be easily extended with the inclusion of liquidity factors, bid-ask spread and depth as further inputs into the operational or market time scale. The use of a dataset containing the shorter end of the yield curve to study the trade intensity dependence among the different yield-to-maturity would also be valuable as it provides a better understanding to the 'missing' factors or driving force behind the dynamics of the yield curve. Leverage effects can also be included in our model by modeling the conditional intensity of price-changing trade as a function of the backward recurrence time of the buy and sell trade to capture the different self and cross-excitations of trades.