The ETF business in the U.S. has grown to about $1.5 trillion but it’s getting harder for firms to launch successful new products due to competition and with most asset classes already covered by existing funds.

“Despite record exchange traded product inflows, a record 102 ETPs closed last year — reinforcing the fact that it has become much more difficult to launch a successful product,” said Credit Suisse analyst Victor Lin in a recent note. “In fact, the percentage of products launched each year that turn out to be successful has been on a steady decline in recent years.”

Other Wall Street analysts following the ETF industry are reaching similar conclusions.

The barriers to entry for new ETFs and firms are “rising – not falling,” says Citigroup analyst William Katz. [Richer Get Richer in ETFs — Harder for New Entrants?]

The so-called Big Three of the ETF business – BlackRock iShares, State Street and Vanguard – control over 80% of the assets.

However, that doesn’t mean it’s impossible for other firms to launch and manage successful ETFs. [Smaller, New ETF Providers Try to Chip Away at ‘Big Three’]