The 1964 Kennedy half dollar is 90% silver, containing 0.3617 troy ounces of silver (0.3255 oz pure). This is the only year Kennedy halves were struck in 90% silver — from 1965-1970 the silver content was reduced to 40%, and from 1971 onward they contain no silver at all.
The 1964 Kennedy half was produced in enormous quantities (over 430 million across Philadelphia and Denver) due to massive public demand following President Kennedy's assassination in 1963. Despite high mintage, they disappeared from circulation quickly as people hoarded them as keepsakes, which is why so many survive in uncirculated condition today.
For silver stackers, 1964 Kennedys offer the same silver content per face value dollar as Walking Liberty and Franklin halves. They're slightly more common and thus trade closer to melt. Their large size and recognizable design make them popular for displays and gifts. Proof versions from the 1964 Philadelphia mint can carry modest numismatic premiums.
Common dates trade near melt. 1964 Accented Hair variety and proof specimens carry modest premiums. The sheer mintage (430M+) keeps prices close to melt.