Hibernate throws org.hibernate.AnnotationException: No identifier specified for entity: com..domain.idea.MAE_MFEView

Why am I getting this exception?

package com.domain.idea;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import javax.persistence.Table;

import org.hibernate.annotations.AccessType;

/**
 * object model for the view [InvestmentReturn].[vMAE_MFE]
 */
@Entity
@Table(name="vMAE_MFE", schema="InvestmentReturn")
@AccessType("field")
public class MAE_MFEView
{
    /**
     * trade property is a SuggestdTradeRecommendation object
     */
    @OneToOne(fetch = FetchType.LAZY , cascade = { CascadeType.PERSIST })
    @JoinColumn(name = "suggestedTradeRecommendationID")
    private SuggestedTradeRecommendation trade;

    /**
     * Most Adeverse Excursion value
     */
    private int MAE;

    public int getMAE()
    {
        return MAE;
    }

    /**
     * Most Favorable Excursion value
     */
    private int MFE;

    public int getMFE()
    {
        return MFE;
    }

    /**
     * @return trade property
     * see #trade
     */
    public SuggestedTradeRecommendation getTrade()
    {
        return trade;
    }
}

Update: I've changed my code to look like this:

package com.domain.idea;

import javax.persistence.CascadeType;
import javax.persistence.FetchType;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import javax.persistence.Table;

import org.hibernate.annotations.AccessType;

/**
 * object model for the view [InvestmentReturn].[vMAE_MFE]
 */
@Entity
@Table(name="vMAE_MFE", schema="InvestmentReturn")
@AccessType("field")
public class MAE_MFEView
{
    /**
     * trade property is a SuggestdTradeRecommendation object
     */
    @Id
    @OneToOne(fetch = FetchType.LAZY , cascade = { CascadeType.PERSIST })
    @JoinColumn(name = "suggestedTradeRecommendationID")
    private SuggestedTradeRe