Basically no there is not. Your best bet will be to setup some intelligent caching within your web layer.
You could define within a config file on the web servers the ticker symbols that you want to cache, then store the values in memory getting new ones every 10-20 seconds or so as needed. This will however mean that you would be sending out old data for that amount of time.
How many records are in your table? You may need to look at you indexes to improve performance. Additional RAM may also help. What does your hardware config look like?