How did Martin Luther, Huldrych Zwingli, and John Calvin differ in their views of Christ’s presence in the Eucharist?

During the Protestant Reformation, Martin Luther, Huldrych Zwingli, and John Calvin held distinct views regarding Christ’s presence in the Eucharist, a disagreement that prevented a unified Protestant front at the Colloquy of Marburg in 1529.12

• Martin Luther: Defending a literal interpretation of "This is my body," Luther maintained that Christ is physically present "in, with, and under" the bread and wine. While he rejected the Roman Catholic doctrine of transubstantiation, he insisted on the real, physical presence of Christ in the elements.34
• Huldrych Zwingli: Zwingli viewed the Eucharist primarily as a symbolic memorial rite and a public declaration of faith. He denied that Christ was physically present in the bread and wine, arguing instead that the elements merely represented Christ’s body and blood.125
• John Calvin: Calvin occupied a mediating position. He taught a "real but spiritual presence" of Christ. Unlike Luther, he did not believe Christ was physically in the elements themselves, but he maintained that Christ is present in the sacramental action, experienced spiritually by the believer.36