Let use an actual example to see if that is the case. The screen capture below shows the bid/ask price of some warrant with delta close to 100% on June 13, 2008. The next screen capture shows the buy and sell price of some counters from SGX on the same date. Noticed in the first screen capture, three out of the four warrants in the screen capture that are very close to expiration have delta close to 100%. This should be the case since the three warrants are deep ITM with around two weeks to expiration. The only warrant with a delta close to 100% and more than two months to expiration is DBS BNP ECW080905. We shall use this as an example.
The second factor to consider is the liquidity of the underlying. Once a warrant is issued, the issuer has to make the necessary hedging arrangements. Buying some holdings of the underlying is one of the methods. If the liquidity of the underlying is inadequate, the cost of hedging will be high. Hence, issuers will work out an estimate of the size of the float of the underlying they can buy or sell at the optimal price before setting the bid/ask spread of the warrant.