Can any please describe to me the difference between the FIFO P&L and MTM P&L on my IB (yearly) statements? The FIFO amount makes sense to me, it's basically the proceeds - cost, but I can't figure out the MTM values. I know IB has a statement out saying that their "cost basis" calculations are incorrect, but it also says the MTM & FIFO P&L calculations are correct. So, can anyone tell me how these two values are calculated and what makes them different? Thank you!