Just for starters, your My Web Search plug-in is generally regarded as malware. Try Googling "my web search plug -in" or use the Search Firefox Help box above Use the quotes. In the box above click the entries even if they seem to be about something else e.g. "Adobe". You should then work your way through(Safe Mode, Problematic Extensions etc) - https://support.mozilla.com/en-US/kb/Troubleshooting%20extensions%20and%20themes The Scottrade site does kick up cpu usage(to around 30% on my Firefox) on loading but immediately settles down.