Average CD rates showed minor downward movement over the past week.

The average 1-year CD rate remained flat at 1.83% APY. The top rate remains at 2% APY and is offered by First City Bank. First City is offering a top rate but be sure to stay under FDIC insurance limits - it is rated as 0 stars according to Bauer Financial for its safety and soundness.

The average 3-year CD rate dropped by 3 basis points from 2.65% APY to 2.62% APY. USAA Federal Savings Bank continued to have the top rate with a 2.81% APY 3-year CD. The minimum deposit for that rate is $175,000. While you need a military connection to quality for their loan and insurance products, you do not need one to take advantage of USAA deposit products. In the banking world, USAA is highly regarded for its banking products and services.

The average 5-year CD dropped 2 basis points from 3.34% APY to 3.31% APY. BankUnited continues to have the top rate at 3.50%. Everbank continues to offer the next highest rate at 3.47% APY.

The chart below shows that CD rates have largely stabilized although there is still a slight drift down in short term rates and savings accounts.

As we noted last week, the spread between short term and longer term deposits remains near record highs, although it dropped very slightly this week (Spread Between Savings Rates and CD Rates Hits Record High).

The elevated ratio means it may be worth taking a look at a longer-term CD, especially one that doesn't have an onerous early-withdrawal penalty. You can now earn 1.5 percentage points more by opening a 5 year CD versus a 1-year CD. If interest rates stay low for the next couple of years, as is possible, then perhaps this elevated spread makes opening the account worth it.

The latest batch of data shows that longer-term CD rate averages are moving up while shorter term CDs as well as savings and money market rates continue to fall. Are we near a bottom?

The chart below shows the rate trends and the uptick in 3-year and 5-year rates over the last two weeks based on the average rates from the BestCashCow rate tables.

The spread, or the difference between the average savings/money market rate and the avarage 3 year CD rate is now at its highest point in over a year. My interpretation is that with rising inflation expectations, banks have to pay consumers more to lock their money up for longer periods of time. Banks can cut short term rates because investors have less places to put the cash that they wish to keep liquid. But if the economy revs up, or inflation rears its head, look for short term rates to begin to rise.

While it's impossible to know for sure, the spread may be an indicator that we have already reached and passed the bottom in longer-term deposit rates and are rapidly approaching that point with savings, money markets and short-term CDs. It may also indicate, as I speculated before the latest stock market rally, that it may be a positive indicator for the general economy and financial markets.

• Compare the best CD rates.
• Compare the best savings rates.

Like dollar cost averaging into an equity security, you can reduce reduce the risk of adverse interest rate changes by dividing your intended CD investment into multiple CDs coming due over various time frames, instead of buying a single CD.

The basic premise of CD laddering is to always have a CD that is coming due in 1 year.

Non-Laddered CD Investing

Suppose you have $100,000 to invest. If you were to have invested this entire amount in 2006 in one year CDs, your returns would look something like the following:

As you can see, the return starts off okay but at the end of the fifth year (2011), interest rates drop and you're stuck investing at 1.2%

CD Laddering

Had you broken the $100,000 into 5 different investments and placed $20,000 each in different term CDs (ranging from say six months to five years), you would have suffered significantly less from the low interest rates in 2010 and 2011, and presumably you would still have some of your money earning higher interest from the longer term CDs.

What laddering does do is smooth out your earnings potential. If rates are high today but drop precipitously in one year you will still have some higher yield, longer term CDs in your portfolio to boost your earnings. Effectively, laddering cushions a portfolio from the steep drop in rates like the one that we have recently seen. Laddering, of course, becomes less effective if rates remain low for an extended period as all of your CDs of various durations will roll over into lower rate replacements.

In some years the laddered approach does better and in other years the non-laddered approach wins. In an extended low-rate environment like today, a laddered approach may be the best way to go. The laddered approach allows investors to earn a better yield on longer-term CDs while still keeping some money relatively liquid in shorter-term CDs should rates begin to rise. Keeping all of your money in shorter duration CDs is better when you are sure interest rates are going to rise, or rates have already begun to go up. Keeping all of your money in longer-term CDs is prudent if you expect rates to plunge, as they did starting in 2008. But, since most of us are not prescient enough to forecast the direction of rates, laddering provides a safe alternative that doesn't require a crystal ball.

Another advantage of laddering is that money comes due every year. Investors that may need the cash at some point, have access to a portion of it every year without having to break a CD and incurring any resulting penalties.

Designing a CD Ladder Today

If one wanted to design a hypothetical CD ladder today, here's how it might look. To get the best rate, we'll use CD rate data provided by BestCashCow. I've looked at both local banks and credit unions (I live near Boston) and online banks to get the best rates for each term. Although this requires a bit of driving around, I've made sure using BestCashCow data that all of the banks have branches relatively close to where I live - within 4 miles.

Investment amount of $100,000

This is the best portfolio I could build. The rates are terribly low and I'm not happy about locking money away for 5 years at 2.40% APY but for all we know, rates might be even lower in five years. After all, in 2008, everyone expected hyper-inflation and soaring rates while the exact opposite has happened. If rates do go up, I can reinvest the money that comes due from the one and two year CDs.

To begin building your CD ladder, spend some time investigating the best CD rates. Get the best rates you can from local banks and credit unions and online banks and then ladder away.