switch from stock to rights?

Holders of CTD should consider switching out of their stocks and into the rights (CTDR):

Pros:
1) the rights are trading for less than the stock price less the offer price ($4.60). Crossing spreads right now with CTD at $5.81 bid, CTDR should be worth at least $1.21 in theory yet you can buy it for $1.03. 18c on $5.81 is a better than 3% boost.
2) you get a free option through till early Jan. If CTD drops below $4.60 you don't have to exercise your rights.
3) you get some (small) interest on the net $4.78 per share from selling CTD, buying CTDR.

Cons:
1) if you're a ST trader looking to possibly exit your CTD holding prior to the rights expiry, you might do worse considering the rights are less liquid and currently trading under fair value.
2) theoretically, the company could call off the offer and the rights would be worthless. Unlikely and if so, CTD could be a lot lower and under $4.60 (depending why it's been called off), in which case you're better off with the rights anyway.
3) depending on your brokerage rates and if you have a minimum brokerage fee, some or all of the current 18c could be eaten up.

Not advice - dyor.