Why not trade bond futures. I know the 10-year note future has an underlying of about $110,000 and an initial overnight margin of about $1,000. That's some pretty good leverage!
Cash haircut on treasury debt is typically 1% with corps up to 5%. Obviously this isn't available to the retail participant. The vig is variable.
what advantage is margin when the underlying moves less than other markets? You need to compare daily ranges with margin to see where you get the most bang. Still though, I would recommend not trading at more than 5 to 1 regardless of exchange requirements ie 1 10 yr contract per 20,000 equity
Statistical vols in the 10s are >6% at 90:1. The only US exchange traded paper-asset with greater available leverage is the CME FX contracts; specifically the EuroFX future at 107:1 haircut at 8% stat vol. The yen may carry a slightly lower haircut. The SGX Nikkei contract carries a very low haircut a well. These contracts are definitely on the top-10 worldwide. More than enough leverage to get someone in serious trouble.
EDs carry lower haircuts, but the stat vols are in the 4% range. Another highly leveraged contract. I don't follow the Euribors.