Advanced P2P Portfolio Calculator

Each position is simulated month by month on its expected path. Starting from the advertised coupon, the calculator removes one cause of leakage at a time:

• Idle cash: the share of your balance that waits uninvested earns nothing, so interest is scaled down by that share.
• Fees: an annual percentage of invested capital, charged monthly on the principal still outstanding.
• Loan defaults: each month a share of the outstanding principal defaults and stops paying interest; the recovered part comes back after a delay.
• Platform failure: each month there is a small chance the platform stops paying; surviving principal is then recovered only in part and late. All positions on that platform fail together.
• Tax: your tax rate on the interest actually received, with withholding tax credited (and any excess reclaimed, if you choose so). Losses are not assumed to be tax-deductible.
• Inflation: the net yield deflated by your inflation assumption gives the real yield.

The break-even default rate is found by raising the yearly default rate on all positions, with your own recoveries and platform risk unchanged, until the net yield falls to 0% (or to your alternative yield). The cushion compares it with the default rate you assumed.

Choosing a platform loads its advertised rate, withholding tax and Due Diligence score from the P2PRadar database, so the calculator and the reviews never drift apart. The platform-failure presets then follow the DD score:

These numbers are stress-test conventions chosen to be cautious, not forecasts and not statements about any platform. Every value can be edited. For how the DD score itself is built, see How rankings work.

Stress scenarios rerun the same cash-flow engine with higher default intensity, lower and later recoveries and, in the crisis case, a forced failure of the largest platform. The matrix applies one default rate and one recovery rate to every position.

The Monte Carlo layer draws a shared credit-cycle factor that scales every position's default intensity in the same direction, an independent pool-quality factor per position, and a failure date for each platform. It is mean-preserving, so the average roughly matches the base case while the spread shows the risk. Results are reproducible for the same inputs.

Concentration uses the Herfindahl index of the share of capital per platform; the effective number of platforms is its inverse.

The projection compounds monthly at the effective annual yield you select and adds the monthly contribution at the end of each month. The real line divides by (1 + inflation)^years.

The goal solver inverts the same formula: for an income target the required capital is the target divided by the monthly net rate, then the contribution needed (or the time to get there) follows.

What is Yield to Maturity (YTM)?

YTM is the total return anticipated on a bond if held until maturity. It is calculated from the purchase price, face value, coupon payments, and time to maturity using the Newton-Raphson method.

What is Weighted Average Duration?

The weighted average duration measures the portfolio's overall sensitivity to interest rate changes, computed as each bond's Macaulay Duration weighted by its share of total investment.

What is Clean Price vs. Dirty Price?

The Clean Price is the bond price excluding accrued interest. The Dirty Price (or Tel Quel) is the actual amount a buyer pays, which includes the Clean Price plus any interest accrued since the last coupon payment. In secondary P2P lending markets, this distinction is important: the seller is entitled to interest earned up to the sale date.

What is Accrued Interest?

Accrued Interest is the interest that has accumulated on a bond since the last coupon payment date but has not yet been paid. When buying a bond on the secondary market, the buyer typically pays the seller the accrued interest on top of the clean price.

• Expected-value paths are smooth; real losses arrive in lumps. Use the stress tests and the Monte Carlo view, not the average alone.
• Tax is a flat rate on interest. Allowances, progressive brackets, loss offsets and the timing of payment differ by country.
• Default and recovery numbers are your assumptions. Platform statistics are often self-reported and can be unreliable.
• Early withdrawals, secondary-market liquidity, currency risk and bonuses are not modelled.