In the model defined below for discount function, are the Beta's relative stable from day to day? If so I might use Hessian dPdB to invert the Beta changes from benchmark price changes, and then to approximate all the other bond model prices in real time. Haven't tried yet, but my intuition is Beta's won't be stable so the approx won't work. thanks in advance if anyone tried this before.
$$ df(t)=\sum_{n=1}^N \beta_n \exp(−n⋅\alpha⋅t). $$