Banks held us all to ransom during the credit crunch – and it looks like they intend to keep doing so.

When rates fell dramatically, they cited funding pressures and passed on only a proportion. In fact, the RBA slashed by 4.25 percentage points in eight months but the average mortgage variable rate dropped only 3.7 points. However, even that seemed generous next to credit cards, which fell by just 1.2 points.

Now that rates are on the way up again they are – you guessed it – citing funding pressures and threatening to raise them more.

So let's look at what's happened so far.

Analysis for AFR Smart Investor by data researcher InfoChoice shows few transgressions on the first rate rise.

After a two-day stand-off, where the big banks held fast to see by how much the others would move and avoid the negative publicity of going first, ANZ did so by just 0.25 points, followed within five hours by the others.

Most lenders increased standard variable rates by that same amount, within a slightly longer-than-average six days (Blue Sky Credit Union and RAMS are two that moved more).

Fixed rates over all periods increased a similar amount in a similar time, although non-banks on average lifted higher. Remember, though, that fixed rates have been rising since April; the average three-year rate, for example, is some 2 percentage points above the 5.5 per cent SVR.

Expectations of the speed of rises increased last week when the governor of the Reserve Bank, Glenn Stevens, said there was a danger in being "too timid" in removing the current emergency levels. But he also noted independent moves by the banks – as threatened – would be taken into account.

So would the banks be justified in such moves? A study by the RBA suggests not.

The June RBA Bulletin found bank funding costs increased almost 1 percentage point with the financial crisis, an amount most have already recouped by failing to move in lock-step with official rates.

The problem is this doesn't matter when the global financial meltdown has put them in a position of power. The Big Four's new home loan market share went from 60 per cent pre-crisis to 81 per cent post-crisis, as consumers fled to perceived safety.

Meanwhile, non-bank lenders that depend purely on money markets for their funding saw that dry up, prompting the Government to inject an extra $8 billion into that market just last week to maintain competition.

Ultimately it is up to us whether we wear excessive increases. Quite aside from relative rate moves, the difference between the best and worst mortgage rate is usually 1.4 percentage points, so chances are you can get a better deal elsewhere.

This will more than likely be from an institution other than a big bank (see our Best Buy tables on page 56) – and latest figures from RateCity, which show the Big Four accounted for only 18.6 per cent of applications through its site in July, suggest we are realising it.

Don't forget, either, that rate rises, while a blow for borrowers are a boon for savers. The very same issue that could see mortgage holders slugged – the difficulty lenders are having raising money in wholesale markets – could see savers rewarded as banks jockey to leverage their advantage: the ability to make up funding shortfalls with deposits. For instance, ANZ lifted some savings rates by double the RBA's move, 0.5 points.

It's not all bad.