With the gas dissolution, the areal density of amphiphiles at the gas-liquid interface of a tiny bubble becomes increasingly high and correspondingly the surface tension decreases. Once the compressed amphiphile monolayer is formed, the bulk nanobubble becomes stable with a vanishing surface tension, even at low gas supersaturation. The findings demonstrate an obvious similarity between bulk nanobubbles and microemulsions. Microemulsions are known to be thermodynamically stable, with a well-interpreted stability mechanism. This similarity inspires us to explore the stability theory for bulk nanobubbles, in analogy with microemulsions. By extending our simulation results, in this work we further propose that bulk nanobubbles can be regarded as gaseous analogues of microemulsions: in microemulsion systems the oil-in-water microemulsion phase coexists with an excess oil phase, while in nanobubble systems it is the gas-in-water nanobubble phase coexisting with the external gas phase (see Figure ). We then analyze the characteristics of stable bulk nanobubbles from the following aspects: i)