VWAP vs Shortfall

[pokhim]

What are the reasons to use VWAP vs implementation shortfall.. i’ve got these off the top of my head but, is this correct?
VWAP: trade is non-urgent, bid-ask spreads are narrow, trade is small compared to total volume.
Shortfall: trade is more urgent, spreads are widers, trade is small compared to total volume
thanks! I’m just updating my notes and want to make sure this is correct.

 

[Galli]

I think that’s right.
Although i’m recalling the VWAP has some dimension of price vol. that skews the prevailing historical prices. VWAP should smooth that out and seek a trade price that reflects the ‘true’ market value of the stock. Idk how that fits into the reasons to use VWAP vs. IS.