The peer-to-peer lending industry in the United States is continuing its upward trajectory with Prosper and Lending Club now having facilitated a total of $800 million in loan volume. Lending Club surpassed $500 million in loan originations this week and Prosper topped $300 million in loan volume earlier this week.

Both companies had a strong lending month in January. Lending Club led the way with $34.0 million in loan originations, up from $31.0 million in loan originations during the month of December. Prosper issued $10.8 million in loan originations during the month of January, up from $9.5 million during the month of December. Lending Club issued 2,602 loans to borrowers during the month and Prosper issued 1,469 loans.

On a year over year basis, Lending Club saw a 229% increase in monthly loan volume compared to January 2011, when it facilitated $14.8 million in loans. Prosper’s monthly loan volume has grown 322% on a year over year basis compared to January 2011, when it facilitated $3.4 million in loan volume.

At current growth rates, Prosper and Lending Club will hit the $1 billion mark in loan originations sometime between May and July of this year. I previously predicted that Prosper and Lending Club will hit $1.4 billion in loan volume by the end of the year.

January was a relatively slow news month for the peer-to-peer lending industry. Prosper was most active in launching a new mobile site and offering a new IRA investment option for investors.