"Peak Prosper" is the point in time when the maximum rate of loan origination is reached, after which the rate of funding enters terminal decline.
Are we there yet? I don't know, but the numbers, IMO, are interesting to observe.
Prosper Total Member Growth
Prosper likes to flaunt their total member count as approaching 900,000.
While technically correct, only 190,000 people have ever registered as borrowers.
Only 93,000 people have registered as lenders.
Then, of course, we know that a significant number of people hold dual roles.
Let us make a generous assumption that NO members hold dual roles - and that these number represent approximately 280,000 unique users.
This means that 620,000 Prosper members have not completed registration to the point of qualifying as a borrower or a lender.
A stunning 68% of Prosper members are not engaged with the platform in a meaningful way.
Membership Growth by Month
For the last 18 months, Prosper has added more than 30,000 new members each month - which I think is quite robust.
The number of people who register as lenders during that same period of time hovers in the 2,000-5,000 range.
For April 2008, the numbers were as follows:
Total Membership Growth: 51,400
New Registered Lenders: 4,640 (9% of total new members for the month)
New Registered Borrowers: 11,200 (21.7% of total new members for the month)
35,560 people (or more than 69% of all new members in April) do not participate in a meaningful way.
Despite this hefty non-growth, the most recent months have seen a significant drop in new members, but I think it's too early to call it a trend.
In March 2007, more than 5,000 new registered lenders joined Prosper (one of Prosper's overall biggest months of total growth: 41,640).
In June 2008, only 2,870 new registered lenders joined Prosper - a decline of 42.7%.
The number of new registered borrowers has been holding pretty steady.
(Note, I am still going on the generous assumption that there are no dual-role holders)
Active Lenders and Borrowers By Month
In March 2007, the total number of Prosper members was 258,750.
In June 2008, that number had swelled to 818,420.
That is a staggering growth of more than 550,000 people - or a 216% increase in just 15 months.
Total funding levels during that same period of time grew from $48,440,000 to $156,310,000 - or an increase of 222%, which seems reasonable and relatively healthy.
The number of active lenders started to flatten significantly after March 2007, at which point the number of active lenders was 12,570.
In June 2008, the number of active lenders was 17,920.
I think it's interesting to note that this only represents a 42.56% increase.
On the borrower side, during that same period, the number of active borrowers grew from 6,460 to 9,490 - an increase of 46.9%.
Borrower/Lender Ratio
The Borrower/Lender ratio has remained quite flat during the period - from a 0.514 in March 2007 to a 0.529 in June 2008.
These are among the very lowest numbers seen during the entirety of Prosper's history.
This is good news for borrowers, but suggests perhaps that too many lenders are pursuing too few loans.
Final Thought
May 2008 saw Prosper having an all-time high of 18,870 active lenders, pursuing close-to-an-all-time high number of 10,110 active borrowers.
As of May 2008, 88,650 people have tried lending money on Prosper (again, a generous assumption, since we know not all registered lenders are actually lending).
During May 2008 - the "hottest" month in Prosper history (at least for Prosper) - only 18,870 people (or a meager 21.2%) had enough interest or confidence in the platform to consider bidding.