If you are not talking to your client about retirement planning, someone else probably is — and stands a good chance of garnering those assets, according to “The Secret Knock: Unlocking the Retirement Opportunity,” a recent report by Pershing LLC and the market research group Mercatus. “For most individuals, their retirement savings are the largest liquid investable assets that they have, so those (advisors) who make it the primary part of their practice are the ones who are more successful and achieve greater share of wallet,” Pershing director Robert Cirrotti says. The nature of the relationship is what's driving the numbers; the retirement-minded advisor provides planning in that segment as a core service and maintains a high level of client contact. For the affluent, retirement is the number-one financial priority, the report says. And it's a big market, with more than $16 trillion in underlying retirement assets in the United States.