Millionaires Have Faith in Bull Market: Study

Finance investor markets happy
Tetra Images | Getty Images

The rise in the Dow has been widening the income gap between the richest and the rest of us.

But another gap has been forming as stocks continue to rally: between wealthy investors who believe the bull market is here to stay and those who are clinging to their doubts.

What separates the believers from the doubters is how much they have to invest.

Tthe stock market is boosting the spirits of all of the wealthiest Americans, according to a survey by Chicago-based wealth research firm The Spectrem Group. The firm's Affluence Investor's Confidence Index, which tracks those with investable assets of at least $500,000, reached a 12-month high in April, as the Dow completed a nearly 13 point rise in that year-long span.

Most of the recent jump in confidence, however, has been driven by those with $1 million or more in assets. That subset of top earners responding to Spectrem's monthly survey said they are encouraged by household income and company health to think that the market will continue its charge. They've been investing accordingly.

(Read more: Diamonds Are an Investor's Best Friend)

"Equity investment among affluent investors rose in April while cash investing decreased," said George H. Walper, Jr., president of Spectrem Group, in the report.

"But among affluent investors" — those with between $500,000 and $1 million — Walper said, "there is still concern whether the recent stock market rallies are real."

For both millionaires and the affluent, confidence hit a low last November, when the "fiscal cliff" negotiations seemed close to spoiling the meager gains the economy had made since the financial crisis. After a deal was struck in January, their outlook soared, according to Spectrem.

(Read more: What's Juicing Stocks and Old Stamps)

The new survey shows that concerns over partisan wrangling continue to wane as a factor in how the rich plan to invest.

That leaves faith in the market as the only guide as to whether to put more money in or sit on the sidelines. So far, all the rich have become richer. But the very rich have become optimistic.