As it is the most meaningful market, Mt. Gox USD is used for this analysis. Any reference to $ or dollar refers to the USD. Dree12 owns some bitcoins. This is not professional advise. Reading this analysis comes at the reader's own risk.
TL;DR: We're over 10x the price 364 days ago, but this isn't going to last.
(The above chart's % indicates the value price / old price, not price / old price - 1. Due to an error, actual values are based on 364-day ranges.)
Labelled: Today, high of 2012, low of 2012, beginning of 2012.
The new year's rally on the 5th and 6th of January 2012 show a massive jump from the slowly rising December values of yearly ROI, reaching a high of 2200% on 2011-01-08. Interestingly, the low on this chart was hit 5 days prior on January 3rd, even though the change on 2011-01-04 was negative. On 2011-01-11, the ROI spiked to 2200% again after two days of lower ROIs due to the higher prices 365 days prior. Since then, the ROI has been decreasing rapidly, and the recent crash brought it down to under 1600%.
The record low on Mt. Gox for this index is barely over 500%. It is likely we will challenge this record in February. The reason is the early February rally of 2011: the price more than doubled in the month of January. With the market as it is right now, we will not be able to double the price to $12 on 2012-02-01. If prices reach $10 by then, the ROI would have been 1300%. Moreover, by 2011-02-09 the price crossed $1, and even optimistically the 2012 counterpart would be hovering in the $10-$15 range at most, putting the ROI at 800%-1300%.
During March 2011, prices corrected and fell below parity with the USD. They then rallied tremendously in April. By 2011-05-08, prices reached $4. Although forecasts this far out are impossible, it is reasonable to assume that barring another bubble, prices would not be over $45 on 2012-05-01. This puts the ROI at most at 1000%, and it is more likely to be less than 500%.
Before mid-May 2011, the prices doubled to $8. Barring another bubble, the 2012 mid-May prices would not be higher than $60. Therefore, the ROI here will unfortunately be stuck in the low positives (<700%); there even exists the possibility of it becoming negatives at this point. On 2011-06-05, the price superrallied to almost $15 dollars, doubling the price again. Again barring another bubble, 2012 prices are likely to be lower than $80 at this point, moving ROI less than 400%.
As we approach June, I will take a closer look at this index. Although we are advertising yearly growth rates of up to 2200% now, it is likely that these growth rates will dip below 0% in a couple months.