I've been experimenting lately with using eSignal's DDE connection to excel only on about 60 stocks and 13 columns of data. I find that during "fast" markets, such as the opening, that eSignal doesn't update data (quotes and charts) though the data is being streamed in. The excel sheet continues to update while eSignal does not until the market slows. A big problem with excel is that updating a lot of cells can be very CPU intensive. I think this is my bottleneck. Has anyone had experience with solving DDE performance issues? An alternative is to use activeX. Has anyone benchmarked differences in processing speed between DDE and activeX?