A butterfly spread consists of 4 trades using three strike prices, with one strike higher, one strike lower and two in the middle with the same strike. All strikes share the same expiration date. The condor is similar but the two middle positions have different strikes.
To enter into a butterfly call spread an investor would buy a higher strike call contract, buy a lower strike call contract, then sell two call contracts of the same strike in the middle. To enter into a butterfly put spread, an investor would buy a higher strike put contract, buy a lower strike put contract, then sell two put contracts with the same strike in the middle.
A condor transaction would follow the same principal with the middle contracts having separate strikes. With this strategy an investor would enter in the trade with the expectation that the underlying will close at or near the middle strike price. Typically, this strategy will have a minimum cost and offers potential for a minimum return with little risk. The investor will know both the highest possible return and the maximum potential loss at execution.
NOT SURE ABOUT DIFFERENCE BETWEEN TRADITIONAL AND MODIFIED BUTTERFLY?