Silverman says that insider stock sales ram up following earnings release. For JP Morgan, that might be especially true for the operating committee, the bank's highest-level brain trust. Company spokesperson Joe Evangelisti said the committee is precluded from selling stock, except within specifically designated windows, most following earnings. "All of their sales will be in these windows," Evangelisti said. "They also hold onto at least 75% of their JPM stock, so they're keeping a lot more than they're selling." Jeff Harte, a principal with Sandler O'Neill who covers bank stocks (including JPMorgan) says he doesn't read such selling activity as a warning sign for the company. "I haven't found that with big banks or brokers, that trends in insider selling have told me all that much – there's a lot of noise," Harte told CNBC, adding that insiders could be cashing out of positions in anticipation of a higher tax bill or for personal reasons not related to the bank's underlying health. (Read More: Hssssss!