Rising unemployment not only displaces workers, it displaces 401(k)s and other retirement accounts, too. And for brokerages, this trend has created a rare opportunity: a chance to steal retirement-account clients from their competitors.

When layoffs occur, some employers automatically clear out the accounts of former employees with balances of $5,000 or less, while others charge higher fees if the former employee wishes to stick with the company plan, says Pamela Hess, director of retirement for Hewitt Associates, a human resources consultant. Hoping to grab these potentially lucrative long-term customers, brokerages like TD Ameritrade (AMTD) and E*Trade (ETFC) are offering cash bonuses of up to $500 and other incentives to those who either open a new IRA or roll over their existing account into one.

Rollover money is very sticky, and very profitable, says Hess. Companies are eager to woo those dollars.

more on those bonuses here. But with retirement accounts, choosing one based on its investment options and fees is much more important.

Also, transferring 401(k), IRA or other retirement account balances is a process rife with potential tax missteps, says Ed Slott, a New York-based CPA who specializes in IRAs. Do it wrong and you may get the $100 bonus, but now the $300,000 you transferred is taxable, he says. (For tips on how to properly roll over your account, ready our story here

Here are some of the bonuses currently being offered:

Bank	Bonus	Details
E*Trade	100 commission-free trades (worth $7.99 to $12.99 apiece)	Open a new IRA by Dec. 31 and receive credits for any stock and options trades made within the first 30 days after the account is opened and deposited funds have cleared. (Maximum number of free trades: 100.)
ING Direct s ShareBuilder	Seven free automatic investments (worth $1 to $4 apiece), and five free real-time trades ($9.95 each)	Open an IRA by April 15, and get seven free automatic investment transactions through the site, which allow you to schedule investments on a weekly or monthly basis. Use coupon code SBIRA09 when you open the account. New customers who roll over a 401(k) or 403(b) also receive five free trades, which expire March 31, 2010.
Scottrade	Refund of up to $100 in transfer fees	Roll over your balance into an IRA and Scottrade will reimburse you up to $100 for any fund transfer fees the other broker charges you. Offer ends Dec. 31.
TD Ameritrade	$100 to $500	Open a new IRA before April 15 and contribute to it within six months. Consumers who roll over retirement balances or other funds worth $25,000 to $99,999 will receive $100. Those who transfer funds worth $100,000 to $249,999 will get $250, and those with $250,000 or more will receive $500.

Data from individual banks.