EFR
Eaton Vance Senior Floating-Rate Fund
stock NYSE Closed Ended Fund

BetaDeltic's SPX box point is the actual answer and worth expanding. A box spread on SPX (deep ITM bull call plus deep ITM bear put, four leg structure) implicitly finances at the EFR plus a small dealer spread. Current rate is around 3.7%. So instead of borrowing at 6% from a bank, you're getting the equivalent of a margin loan at near risk free rate, with no fixed repayment schedule and no underwriting risk. The 2.3% spread between your 6% bank rate and the box rate is pure friction you can avoid.
Beyond that, the math on the bank loan path is worth doing carefully.
100k at 6% debt service is 6k yearly. Gross trading return at 40% on doubled book is 80k. EU tax on options income depending on jurisdiction is typically 20 to 26% as capital gains, so net of tax is around 60k. Slippage and capacity drag at doubled size for a positive skew scalping strategy is real because your edge per trade compresses when fills get worse, conservatively another 3 to 5 points off the gross return.
Net 25% effective annualized return on the borrowed capital after tax, debt service, and capacity drag. That's still good but it's not the 40% you've been earning unlevered. And the variance widens significantly because the debt service is fixed and the returns are bumpy.
The drawdown timing problem is the one nobody else flagged. A 4 to 6 month flat or losing stretch means you're paying loan service from somewhere else (savings, credit cards, etc) while your trading capital is underwater. That's the moment positive skew strategies blow up because the psychological pressure to size up to make it back is highest exactly when the strategy edge is weakest.
If the goal is genuine scale, the SPX box route plus a smaller bank loan (pagalvin's 25k point) gives you most of the upside with much less of the structural risk. Doubling capacity through expensive debt on a strategy with unknown drawdown profile is the highest risk path to the same return target.

BetaDeltic's SPX box point is the actual answer and worth expanding. A box spread on SPX (deep ITM bull call plus deep ITM bear put, four leg structure) implicitly finances at the EFR plus a small dealer spread. Current rate is around 3.7%. So instead of borrowing at 6% from a bank, you're getting the equivalent of a margin loan at near risk free rate, with no fixed repayment schedule and no underwriting risk. The 2.3% spread between your 6% bank rate and the box rate is pure friction you can avoid.
Beyond that, the math on the bank loan path is worth doing carefully.
100k at 6% debt service is 6k yearly. Gross trading return at 40% on doubled book is 80k. EU tax on options income depending on jurisdiction is typically 20 to 26% as capital gains, so net of tax is around 60k. Slippage and capacity drag at doubled size for a positive skew scalping strategy is real because your edge per trade compresses when fills get worse, conservatively another 3 to 5 points off the gross return.
Net 25% effective annualized return on the borrowed capital after tax, debt service, and capacity drag. That's still good but it's not the 40% you've been earning unlevered. And the variance widens significantly because the debt service is fixed and the returns are bumpy.
The drawdown timing problem is the one nobody else flagged. A 4 to 6 month flat or losing stretch means you're paying loan service from somewhere else (savings, credit cards, etc) while your trading capital is underwater. That's the moment positive skew strategies blow up because the psychological pressure to size up to make it back is highest exactly when the strategy edge is weakest.
If the goal is genuine scale, the SPX box route plus a smaller bank loan (pagalvin's 25k point) gives you most of the upside with much less of the structural risk. Doubling capacity through expensive debt on a strategy with unknown drawdown profile is the highest risk path to the same return target.