A few of Binance's main bStocks can now basically be used directly as Margin collateral.
MUB, SNDKB, and SPCXB were added by Binance on July 3:
• Full‑position leverage Cross Margin
• Unified account Portfolio Margin
• Unified account professional version Portfolio Margin Pro
SKHYB was also added to these three systems on July 13.
It should be noted that these assets are currently used mainly as "collateral" and cannot be lent out directly.
The logic of ordinary Portfolio Margin is very simple:
Effective margin value = RWA market value × collateral rate
For example, assume SPCXB's collateral rate is 70%:
Holding $1,000,000 SPCXB
→ Only $700,000 is counted toward margin equity
→ Equivalent to a 30% haircut
So the focus is not “whether it can be used as margin,” but rather what collateral rate Binance ultimately assigns to the asset.
The official calculation for BTC is the same: if BTC's collateral rate is 95%, then 3 BTC are ultimately counted as only 2.85 BTC worth of margin equity.
Portfolio Margin Pro goes a step further.
PM Pro does not give a fixed collateral rate; it uses a "tiered collateral rate."
The structure might look like:
$0–100k: 100%
$100k–250k: 80%
$250k–500k: 50%
$500k and above: 10%
Note that this is tiered calculation, not that everything suddenly becomes 10% after the position exceeds $500k.
Therefore, the larger the position size, the lower the marginal collateral efficiency of additional positions.
This is actually quite important.
It means that bStocks such as MUB, SNDKB, SPCXB, and SKHYB not only provide stock‑price exposure but now also add a layer of capital efficiency:
You can continue to hold RWA assets while using them as margin for the unified account to trade perpetuals, futures, or other portfolio trades.
The core of what really needs to be examined boils down to two points:
How high is the specific collateral rate for each bStock?
After large‑position holdings in PM Pro, how severe is the tiered haircut?
If the collateral rate is high enough, the capital utilization efficiency of these bStocks can be far higher than simply holding the spot asset.
